Shape

Being a right-handed ergonomic mouse, the M4 has the shape attributes one would expect: a fairly narrow front which organically extends towards the back and a slightly raised left side. While the mouse curves inwards on the left side, it curves outwards on the right side, creating a slight shift between the top and the bottom. What makes the M4 special, however, are two things: The curves aren't as aggressive as on many other ergo mice, which makes the M4 more akin to an ambidextrous mouse in terms of handling. Additionally, despite the slight raise on the left side, the hump is quite "flat" due to extending across the entire width, coupled with a gradual slope across the longitudinal axis. The raised left side also ensures that there is enough space for the thumb. Overall, it's a fairly unique shape that handles very well.



As for grip style, I'd say the M4 suits all three main grip styles (palm, claw, and fingertip). Despite having a right-handed ergonomic shape, the M4's curves are neutral and non-intrusive enough to allow for many ways of gripping the mouse. It's a medium-sized mouse and should therefore suit most hand sizes. For reference, my hand size is 19x10 cm, and the M4 feels very comfortable in claw grip.


Another design choice worth mentioning is the addition of holes in the mouse body. Their main purpose is to save weight, of course. The M4 has holes all over the sides too, however, which is both a positive and a negative. On the one hand, the holes do provide additional grip, which is especially welcome given the M4's low weight. On the other hand, the holes are prone to getting dirty over time (dead skin cells), and cleaning these tiny holes is a rather tedious undertaking.

Dimensions

This table includes the dimensions of the Xtrfy M4 and several other right-handed ergonomic mice. "Front height" denotes the distance between the base and main buttons. Measurements with two decimals have been taken with a caliper, while those with one decimal have been taken with a ruler. For a full list of all measurements taken, please refer to this sheet compiled by an esteemed community member.


Here are some comparison shots with each of the measured mice:


Roccat Kone Pure Owl-Eye


SteelSeries Rival 310


Zowie EC2-B