If your wrist is tired, your desk is cramped, and your pointer finger is ready for retirement, the ProtoArc EM05 NL might be worth a look. This curious little hybrid peripheral combines a thumb-controlled trackball with a vertical mouse shell, creating a rare ergonomic design that feels familiar for people used to traditional mice, but also adds comfort for strained wrists.

The EM05 NL doesn’t come packed with premium features, but at $59.99, it’s not trying to. It's built to let you get on with your computing tasks and get out of your way. It’s designed for people who work across devices, stay at their desks for hours, and want something easier on their bodies than a standard mouse. It also stands out as one of the few mice on the market that attempts to combine vertical orientation and trackball control in a truly portable form factor. It's a tempting alternative to the superior but pricier Kensington Expert Mouse Wireless Trackball, our current Editors' Choice pick for the category.

First Impressions and Setup: Minimal and Functional

Right out of the box, the EM05 NL gives off a clean and efficient vibe. The matte black body feels sturdy enough for daily use, and the soft side grips help keep your hand secure without feeling rubbery. It ships with a USB-A 2.4GHz dongle, a USB-C charging cable, and a printed quick-start guide. The packaging is minimal and functional, just like the mouse itself.

(Credit: Joseph Maldonado)

Pairing is quick and painless. The EM05 supports Bluetooth 5.1, Bluetooth 3.0, and 2.4GHz wireless, and you can connect up to three devices at once. A physical switch on the underside lets you toggle between them. During testing, I moved seamlessly between a MacBook, a Windows 11 desktop, and an Android tablet. Device switching was immediate and hassle-free.

Design and Ergonomics: A Comfortable Handshake Posture

The 62-degree tilt isn’t as steep as the more dramatic Evoluent designs, but it offers a welcome wrist angle for those transitioning from a traditional mouse. The handshake posture reduces forearm pronation and encourages a looser, more relaxed grip. This design promotes healthier arm movement over time, a phenomenon that becomes especially noticeable after multiple consecutive full workdays.

(Credit: Joseph Maldonado)

The thumb-operated trackball is nestled comfortably in a concave space on the left side of the device and is easy to roll without lifting your hand. It’s a clever placement that avoids fatigue and awkward positioning, though it may not be ideal for users with unusually large thumbs or those used to finger-driven trackballs.

(Credit: Joseph Maldonado)

The EM05 is compact, more so than some other vertical mice. It’s best suited for small or medium hands. Users with larger hands may find that their pinky or palm spills over the base, although the contoured shape still provides a stable resting platform. The slightly raised heel and thumb scoop offer enough guidance to keep your hand in place during extended use.

The mouse includes standard controls: left and right clicks, a clickable scroll wheel, a DPI toggle, and forward/back thumb buttons. There’s also a clickable trackball, which some users may map to middle-click functions depending on which OS they're using. The button feel is adequate, though slightly shallow. The EM05 offers no click customization or macro programming, and you won’t find any silent-click mechanics or haptic feedback features here.

Performance in Daily Use: Precise Cursor Placement

Cursor control with the EM05 is handled entirely through the trackball, which may take some getting used to. Once you're familiar with it, the experience is smooth and surprisingly efficient. The ball rotates 360 degrees, allowing for precise cursor placement with minimal effort. Unlike traditional mice, you never need to lift or drag the EM05, making it well-suited for people with limited desk space or mobility restrictions.

(Credit: Joseph Maldonado)

DPI adjustment is built in, with five preset options: 200, 400, 800, 1200, and 1600. Switching is done via a small button behind the scroll wheel. The lower DPI settings are ideal for precise control, while the upper range is helpful for broad gestures across larger screens. The lack of fine-tuning or user-defined DPI steps is a limitation; however, for an office-focused device, the defaults are sufficient. For most people, 800dpi hits the sweet spot for general desktop use.

While the EM05 is not ideal for gaming or design work, it handles office tasks like document editing, web browsing, and spreadsheet management with ease. The vertical grip also reduces fatigue over longer sessions, a benefit I noticed after several hours of uninterrupted use. I was able to complete an 8-hour writing day without the wrist soreness that sometimes occurs when using flat, low-profile mice.

Battery Life and Charging: Don't Forget to Plug In

ProtoArc advertises a 500mAh rechargeable lithium battery, and in testing, that translated to roughly 5 to 7 days of moderate daily use before needing a recharge. Charging is handled via USB-C, and the mouse is fully usable while plugged in. The inclusion of USB-C rather than micro-USB is a welcome modern touch, and the charging cable is long enough to reach across a typical desk setup.

(Credit: Joseph Maldonado)

There’s no dedicated software to monitor battery levels. A small LED indicator flashes red when power is low; however, you must monitor performance or establish a regular charging routine to prevent downtime. It would be a nice upgrade to see a percentage-based indicator or a charge level visible on the host device, but in practice, the battery life is long enough that most users will rarely run it down entirely.

Connectivity and Compatibility: Multiple Options

One of the EM05’s strengths is its triple-mode connectivity. With support for both modern and legacy Bluetooth protocols, as well as 2.4GHz wireless, it plays well with nearly any device. Switching among paired devices via the underside toggle was smooth and delay-free during testing.

(Credit: Joseph Maldonado)

I used the EM05 with Windows 11, macOS Ventura, and Android 13. All connections were stable and responsive. Note: the forward and back buttons are not compatible with macOS, a limitation that may frustrate some Apple users. For general navigation and control, however, the mouse worked seamlessly across platforms.

There is no companion app or driver for button customization, DPI tuning, or firmware updates. This may be a deal-breaker for users who like granular control over their input devices, but for plug-and-play simplicity, it performs as advertised.

Trackball Maintenance: Cleaning Required

The trackball mechanism is impressively smooth when clean, but as with all thumb-operated trackballs, occasional maintenance is essential. The ball can be easily popped out for cleaning using a soft cloth or compressed air. A quick wipe every few days kept the movement consistent. If you’re using it in a dusty environment or tend to snack at your desk, a microfiber cloth nearby is a smart companion.

It’s worth noting that, unlike larger trackball mice, the EM05 doesn’t offer a deeply recessed or oversized ball. This makes it easier to operate quickly but may slightly reduce fine control for those used to large, finger-controlled trackballs. Still, for general office productivity and even light media editing, it holds its own.

ProtoArc EM05 NL Alternatives: It's a Niche Market

Few mice combine a vertical shape with a built-in trackball. The Logitech Ergo M575 remains a favorite in the trackball-only category, and Logitech’s Lift caters to ergonomic needs, but neither offers the hybrid design of the EM05. In this sense, the EM05 serves a largely ignored user base: individuals who want to reduce wrist strain without sacrificing desk space or flexibility.

Compared with the ProtoArc EM11, the EM05 is more compact, with a slightly less aggressive tilt and a sleeker build. It’s better suited for smaller desks or portable setups. While it drops some flexibility in terms of features, it retains the core ergonomic design principles that make these devices appealing.

And while it may not replace a high-end vertical mouse for those with complex workflows, it adds value as a secondary or travel mouse for users who want to stay comfortable no matter where they’re working.