ProtoArc is known for making all sorts of office products with a big focus on ergonomics and comfort. Its latest product, the EM25, promises a comfortable-to-use, affordable, and customizable mouse. We took one for a spin; here are our impressions.
The ProtoArc EM25 is a $49.99 mouse, but right now, during Prime Day 2026, you can get it for just $37.99. Right off the bat, you can see that the EM25 is inspired by Logitech's MX Master lineup and the legendary MX Master 3/3S. Its shape and proportions are very similar, so for a person with large hands (right-handed person, mind you), the EM25 is very comfortable to use. The mouse fills the palm, and the thumb rests on a small extension, giving your wrist a small tilt to reduce strain.
The mouse is made of black plastic without any coating, eliminating long-term wear concerns. However, I can see the main buttons and other areas you touch the most getting polished over time. Despite its size and bulk, the mouse is not too heavy. It weighs about 100 grams, which is significantly less than the MX Master 3S and its successor. It is no lightweight gaming mouse by any means, but it is not excessively heavy like the MX Master 4.
The EM25 has a built-in storage for its USB dongle. It is a cleverly made magnetic flap that you open by simply pressing on it. Next to the flap, you will find the on/off switch, the 1,000 Hz sensor, and a DPI button (up to 8,000 DPI). I find the DPI button location a bit odd, and I would prefer it somewhere below the main scroll wheel. Still, given that I never change DPI on my mice, I will let it pass.
