Roller Mouse Pro 2 has an integrated optical input device that spins on a horizontally mounted shaft for up and down movement and slides left and right to control left and right cursor movement. The roller also may act as a primary (left mouse button) by depressing it. Mousing is done from the midpoint so there is no need to abduct the shoulder or elbow. Wide roller, large, easy to click buttons, and two new buttons have been added (Copy & Paste), making PRO 2 the best choice for high speed, safer mousing. The newest 800 dpi resolution allows more precision for special applications. Black Only. Adjustable lifters with 3 height adjustments, gets your keyboard to a comfortable height. (many keyboards are getting thinner these days). You can even get the Apple wafer thin keyboard up to a comfortable height to avoid accidental striking of the roller. Keyboard stays put when operating thanks to the sure gripping surface of the two lifters Three locations for lifter placement allow for today's wide or narrow keyboards New softer gel palm supports with a leatherette finish are easy to clean. More »