Shape

A trait the vast majority of right-handed ergonomic mice have in common are their curves, which are meant to organically accommodate the shape of the human hand. Typically, the left side in particular curves inward in order to create a natural resting place for the thumb. The Kain 100 radically breaks with this idea. While the general contour of ergonomic mice is still in place with the left side raised and a gradually sloping hump, the sides are almost completely straight, both vertically and horizontally. Although the body gradually widens towards the back, a flare at the front or back is notably absent. Keeping the sides this straight would be a bold move even for an ambidextrous design. For an ergonomic mouse, it's wholly novel and unique, especially considering previous ROCCAT mice were known for having curves upon curves.


Yet, surprisingly enough, the design of the Kain 100 works very well in practice. The lack of curves gives the fingers room to breathe, and with no parts of the mouse body in the way, it is easier to place them as one likes. Deep curves can help fingers stay in place for a secure and firm grip, but they also restrict preferred grip styles to certain configurations which may or may not line up with one's individual preferences and inclinations. In a sense, the straight sides of the Kain 100 allow one's individuality to take form.


Having said that, the straight sides introduce an additional restriction: grip width. The lack of curves results in the mouse being quite wide, significantly wider than many other similarly sized right-handed ergonomic mice, in fact. Smaller hands will inevitably struggle with the sheer width of the Kain 100. For this reason, I'd mostly recommend the Kain 100 for larger hands. As for grip styles, I'd say the Kain 100 can be used just fine in all three main grip styles—palm grip, claw grip, and fingertip grip. For reference, my hands are 19 cm long and 10 cm wide, and I found the Kain 100 very comfortable in claw grip.

Dimensions

This table includes the dimensions of the ROCCAT Kain 100 AIMO and several other right-handed ergonomic mice. "Front height" denotes the distance between the base and the 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:


Logitech G403


Glorious Model D


Xtrfy M4


ROCCAT Kone Pure Ultra