That is the Logitech M525 wireless mouse, a rather unassuming hunk of plastic and rubber with a scroll wheel that also tilts for navigating pages both horizontally and vertically. Sure, you get your choice of white or black, for what that's worth, but probably the most distinguishing feature is the battery life. This £35 ($40) pointer gets up to three years on a single pair of AAs.
WOW, 3 years, i bet the life reduce with excessive use.