The new Mus model has a scroll wheel. The scroll wheel also performs the right click action. Compatible with Windows and Mac OS X. Mus3 cordless optical mouse not only controls the cursor on the screen, but cleverly looks like one, too. Despite its unconventional shape, Mus3 fits well into your hand and feels comfortable. Signal range of at least 2 meters. A built-in power indicator in the handle lights up when the batteries are low or need replacing.