This is a refurb Apple Pro Mouse. The mouse works properly but ma have light scratches on the casing. The Apple Pro Mouse has no rollers or tracking mechanisms to wear out or clog, and no mouse balls to fish out and clean. Besides all that, there's no distinguishable mouse button. Instead, the entire Apple Pro Mouse is in effect a super-sensitive button - the body pivots up and down to actuate the click mechanism. It even lets you fine-tune the way it clicks, with user-adjustable click tension. The elliptical shape equally accommodates right and left-handed users, and its glass-smooth surface makes it a joy to use. Need a higher degree of precision? When working with applications like Photoshop or Illustrator, the Apple Pro Mouse hits 400 dots per inch resolution at rates of motion up to 14 inches per second. This means the Apple Pro Mouse maintains accuracy at faster speeds - letting you move 15% faster than you could with other optical mice. Features High-precision digital optical tracking Comfortable elliptical shape Easy-to-use, full-surface button Adjustable clicking tension Compatible with all USB-enabled Apple computers Elegantly designed to integrate the mouse button into a seamless enclosure — making it a pleasure to hold and intuitive to use. Click the Apple Pro Mouse any way you like — there’s no need to hit a button with a particular finger or in a certain way. You’ll never have to worry about the Apple Pro Mouse clogging or losing its precision. Glides effortlessly over your desktop, using an optical sensor instead of a traditional mechanical ball to translate mouse movements to the screen pointer. Lets you adjust its click-tension to suit the way you work and play.