Has a tilt of 20º so it is a bit like a vertical mouse. Which makes it strain less the wrist.

Metal plate gives heft, rubber on top and bottom give grip and incredible comfort

The center button goes left or right which is a really useful feature, and those are also programmable.

Allows having a profile per-application. Requires the Logitech options software.

Most buttons, left and right buttons aside, are configurable to a list of actions ranging from mouse clicks to custom keyboard combinations or none at all. Requires the Logitech options software.

Can be connected using Bluetooth or the Logitech unifying receiver.