ProtoArc EM03 NL Review – A Modern Ergonomic Trackball with a “Center Ball”

I’ve been using trackballs since the ’90s—both on the Amiga and on my first Windows PC. And when it comes to trackballs, there are two fundamentally different designs. One has the ball in the center, as with the ProtoArc EM03 NL reviewed here, for control with the index and middle fingers—and the other has the ball on the side for control with the thumb, as is the case with the sister models EM01 and EM05 NL. Which design you prefer is a very personal matter. I, for example, get along better with the “center-ball” design—probably just out of habit.

However, there was one major problem: there has been virtually no innovation in new products on the market for decades. For instance, I was already using the Kensington Orbit Trackball with Scroll Ring 15 years ago—and it’s still sold today in virtually the same form. Before that, I’d used the version without the scroll ring—and that one is still available in the same form. Later, the Kensington Expert Trackball was added to the lineup; it’s been around just as long, but despite its high price, it didn’t win me over. And that pretty much covers the range of options. Or so it seemed. Because with the ProtoArc EM03 NL, there’s actually some movement in the market again after many years, and I’m really looking forward to testing it—especially when compared to the older competitors.

Specifications

Dimensions	16.8 x 10.5 x 5.5 cm
Ball Size	44 mm
Connection	Wireless via USB and Bluetooth 5.0
Compatibility	Windows XP and later (USB), Windows 8 and later (Bluetooth), Mac OS X 10.12 and later, Android 4.3 and later (Bluetooth), iOS
Sensitivity	200 / 400 / 800 / 1200 / 1600 DPI
Battery	500 mAh
Wireless range	10 m
Warranty	2 years
Price	€53.99

Packaging and Contents

• Packaging with a professional design
• The manual is multilingual and well-translated
• A charging cable is included

The ProtoArc EM03 NL comes in dark gray packaging that conveys a sophisticated and professional, yet understated aesthetic. The box is easy to open, and you’re greeted by a small black envelope and a quick start guide. Inside the envelope, you’ll find a service sticker and some information about ProtoArc. Not very helpful, but it reinforces the premium impression.

Further down, you’ll find the trackball itself, protected by a plastic film. There’s also an accessories box containing a charging cable and the user manual. The manual is available in multiple languages—English, German, French, Italian, Spanish, and Japanese. And the translation is quite useful and easy to understand.

Design

• Matte black finish
• Quite large
• Scroll wheel stands out visually

The ProtoArc EM03 NL is a matte black, ergonomic trackball. The color of the ball is the one customizable feature. In this review, I’m testing the version with the dark gray ball, but it’s also available in red and purple. One thing that stands out is the orange scroll wheel, which—along with the gray ball—is the only pop of color and doesn’t quite match the other ball colors. I think I would have stuck with the color scheme of the other models, the EM01 and EM05 NL, and installed a black-and-silver wheel.

The EM03 is a fairly large device, and my hand (glove size 9.5 or L) rests completely on it. Most mice—and even the most similarly priced trackball competitors from Kensington—are noticeably smaller. Visually, the ProtoArc’s ball therefore appears relatively small, but at 44 mm, it’s actually quite large. Operating this trackball becomes more difficult for people with small hands. This is likely to hinder its ergonomic benefits as well.

Aside from the orange scroll wheel—which would look better on a gaming mouse—the ProtoArc EM03 NL definitely makes a very professional, “business-like” impression. Don’t get me wrong: in terms of functionality, the scroll wheel works just fine. It just seems out of place from a design perspective.

Build Quality and Handling

• Good build quality with no creaking plastic noises
• The ball can be easily removed for cleaning
• The surface tends to develop dark, shiny spots

After years of using the Kensington Orbit Trackball with Scroll Ring, the build quality of the ProtoArc EM03 NL really stands out as excellent. I’ll be using this Kensington trackball as a reference more often, since the selection on the market is very limited and this model is the most comparable in price and the most prominent competitor in this category. The EM03 feels noticeably better in the hand. If you’ve been used to the Kensington for years, the ProtoArc really feels like a significant step in the right direction, especially since the ProtoArc has adjustable DPI and forward/back buttons, which are helpful for browser navigation.

To come back to the scroll wheel: It worked without any issues, but with some fast movements, a squeaking sound could be heard, which doesn’t quite fit with the otherwise good impression.

The ProtoArc EM03 NL has three sturdy non-slip rubber feet on the bottom. Since trackballs are meant to stay in one place anyway and don’t require a textured surface, a mousepad isn’t necessary.

However, shiny fingerprints are quickly visible on the trackball’s matte surface. But you can also use these as an indicator of when it’s time to clean it.

Regarding cleaning: To do this, you can reach through the bottom of the housing to remove the ball. Then you can also clean the interior and the sensor.

So, this trackball generally makes a good impression in terms of build quality, but it doesn’t quite match the feeling of sturdiness conveyed by its sister models, the EM01 and EM05, which feature thumb controls.

Setup and Connection

• Connection via USB dongle or Bluetooth
• The dongle can be stored directly inside the trackball
• Reliable connection

Setting up the ProtoArc EM03 NL reviewed here is simple, as it requires no software or manual drivers. Just plug in the USB dongle, turn on the trackball using the switch on the bottom, and check to see if the LED next to the dongle icon is flashing. If it isn’t, press the small button between the three LEDs and the on/off switch until the desired mode starts flashing. Alternatively, you can connect the EM03 NL via Bluetooth. To do this, select either Bluetooth 1 or Bluetooth 2. Then, simply search for “ProtoArc EM03 NL” in the Bluetooth connection settings of the device you want to connect to, and you’re ready to pair it. This makes it easy to switch between multiple devices—for example, you can plug the USB dongle into your desktop computer while also connecting two other devices, such as laptops or tablets, via Bluetooth. You can then use the button to switch back and forth between the devices. This is handy if you use multiple computers and want to switch between them without cluttering your desk with mice or having to constantly swap out USB dongles. Plus, when using Bluetooth, you won’t lose the USB dongle if you take the trackball with you to use it on a laptop while on the go.

I have to say that I’m very satisfied with the connection setup here. It worked very easily and very reliably. The USB dongle connection is the fastest, whereas Bluetooth typically takes a few seconds to re-establish the connection. One advantage of the Bluetooth connection is that it lets you check the remaining battery level. You can’t use the USB cable for this—it’s only included for charging the battery.

First Impressions and Practical Use

• Ergonomic design for a comfortable hand rest and grip
• It takes some time to get used to it
• Button actuation point is somewhat soft

If you’ve been using Kensington’s symmetrical trackballs for years, the design of the ProtoArc EM03 NL feels noticeably different. Of course, this trackball is ergonomically designed for right-handed use, whereas symmetrical trackballs are more advantageous for left-handed people who actually use the mouse with their left hand. But realistically speaking, there are simply more right-handed people—and some left-handed people who still use their right hand for the mouse. And in this case, it’s simply more comfortable to have an ergonomic design optimized for that. Your hand rests comfortably on it and isn’t twisted as much as it is with non-ergonomic models. This helps relieve strain on the wrist.

The left mouse button is pressed with the thumb, and the right mouse button with the ring finger, which—like the little finger—is held in a fixed position by a gentle indentation. The scroll ring and “forward and back buttons” for browser navigation are also operated by the thumb. In that regard, I feel like I would have preferred the scroll wheel to be on the right side of the trackball, so I could use my middle finger to control it in a more familiar way, as is typical with standard mice. But that’s probably just a matter of getting used to it.

During this test, I occasionally noticed that I found the click point of the buttons a little too “soft.” In particular, I triggered the “middle” mouse button—that is, the pressure on the scroll wheel—more often than I was used to with other models while scrolling. But the other buttons were also very easy to press, so that simply resting my fingers on them almost caused the buttons to be activated. The amount of force required is correspondingly low. With the forward and back buttons, however, this wasn’t a problem.

After a period of inactivity, the trackball enters sleep mode to conserve power. To wake it up, you have to click—simply moving the ball isn’t enough.

Work and Gaming

• Optimized for Office Work
• Very quiet buttons
• Gaming is possible, and the best way to do this is via a USB dongle

Even back when I was using other trackballs, colleagues would say that they were more suited for gaming, while gamers would say they were better for professional work. I have to say that it’s purely a matter of getting used to it, and everything can work well with it. Nevertheless, the ProtoArc EM03 NL is conceptually designed for ergonomic everyday use rather than gaming. In an office setting—especially when you’re sitting next to other people—it’s nice that the mouse buttons are very quiet, so you don’t annoy your coworkers with clicking noises. And here, the health aspect—thanks to the ergonomic design—is more important than performance. I also find it easier to work precisely with the large trackball than with the smaller ones on thumb-controlled models. The trackball just feels a bit more substantial and smooth.

But in principle, you can of course also use the trackball for gaming once you’ve gotten used to it. In this case, the USB dongle connection is more suitable, since the transmission runs at 250 Hz instead of 125 Hz over Bluetooth—which isn’t really relevant for work. So, optimization for the work environment doesn’t inherently get in the way of gaming. Here, too, you benefit from a healthier hand posture, though the learning curve might be a bit steeper.

You can also adjust the sensitivity to your liking. It starts at 200 DPI, which feels too slow for everyday use, but it allows you to make small movements with great precision. Depending on personal preference and screen resolution, I consider 400 or 800 DPI to be the most practical sensitivities for everyday use—you can move quite quickly from one side of the screen to the other while still being able to handle details well. 1200 and 1600 DPI make the cursor move quickly, but I find that impractical for work scenarios. However, depending on the game and controls, this could work well for gaming.

Depending on your work computer, it’s also nice that a Bluetooth connection is available, since some particularly slim laptops these days no longer come with a USB-A port to use the dongle. This connectivity option also ensures that the trackball won’t become obsolete too quickly if you switch devices.

Battery life

• Long battery life
• Battery life is extended by automatically activated sleep mode
• Battery charge level is displayed via Bluetooth, not via USB

The ProtoArc EM03 NL’s built-in battery has a capacity of 500 mAh. At the start of the testing period, I charged it once using my computer’s USB port, which took about an hour. After that, I just used it. You can’t check the battery level via the USB port, but you can see it via Bluetooth. I’m not sure how accurate this reading is, though. Even after two weeks of intensive testing, it was still showing 100%. Even if those figures are just rounded to the nearest 10%, that would still be absolutely great. So you don’t have to worry about having to recharge it constantly. After a single charge, you can probably go a few months without having to recharge.

The ProtoArc product page states that the battery has a runtime of up to approximately 1,440 hours. Even that would be two months—with continuous use. But after a few minutes of inactivity, the trackball goes into sleep mode. With normal use, you should hardly need to charge the battery more than 2–3 times a year.

Comparison with the Competition

• Similar price range and target audience
• The ProtoArc EM03 NL is superior in most aspects regarding operation and build quality
• Kensington is more compact and, as a symmetrical model, can also be used with the left hand

In many product categories, there is so much choice that it hardly makes sense to make comparisons. In the category of trackballs with a centrally located ball, however, competition is limited, so there’s a high probability you’ll come across the Kensington Trackball with Scroll Ring, which falls in the same price range and which I’ve already mentioned in the ProtoArc EM03 NL review. Here, I think a direct comparison makes sense.

What isn’t immediately apparent from the picture: The ProtoArc EM03 NL is significantly larger. The Kensington trackball originally came with a palm rest, but over time it developed stains that couldn’t be removed—especially since it wasn’t permanently attached and often slipped out of place. There was also a noticeable edge here. Consequently, I eventually discarded the palm rest from the Kensington trackball. In this regard, the overall ergonomic design of the ProtoArc EM03 NL is much more practical than the add-on part.

The EM03 has even more advantages: The buttons are quieter, and it not only has two buttons—like the Kensington—but also forward and back buttons, as well as a “middle” mouse button activated by pressing the scroll wheel. Furthermore, you can adjust the DPI on the ProtoArc, which isn’t possible on the Kensington: Movement too fast or too slow? Too bad. Here, only the limited settings in the operating system are available. Then there’s the connection: The Kensington has a permanently attached USB cable, whereas the ProtoArc EM03NL—despite its comparable price—is a wireless trackball—and even offers multiple connection options.

Furthermore, the ProtoArc makes a slightly better impression in terms of build quality: the Kensington occasionally creaks, and the rubber feet are also significantly thinner—no such issues with the ProtoArc. And its trackball is also slightly larger, allowing it to roll more smoothly.

Still, I can’t quite declare the EM03 the outright winner, even if it’s not far off. The Kensington trackball is more compact and therefore easier to slip into a laptop bag, plus, its symmetrical design is suitable for left-handers, and the scroll ring around the ball is comfortable to use, especially since you can choose whether to rotate it with your thumb, middle finger, or ring finger.

Conclusion

Great. Right-handed users looking for a trackball with a centered ball have had very limited options until now and have had to settle for models that required quite a few compromises. Admittedly, one more model on the market doesn’t exactly represent a huge increase in choice. But with the ProtoArc EM03 NL, I feel like I don’t have to trade the advantages of a trackball for the drawbacks of mediocre build quality, limited buttons, or restricted control. Add to that the very quiet buttons, the ergonomic design, and a price that doesn’t seem out of reach.

There are certainly a few details I’d like to see done a little differently, but overall, the ProtoArc EM03 NL is a trackball I wish had existed years ago. So, as far as I’m concerned, I definitely recommend it to anyone looking for a trackball in this category. One small caveat: For left-handed use, only the symmetrical models remain an option.