Mouse - SODIAL(R) Black Wireless 2.4GHz Optical Hand-Held USB Trackball Mouse For Laptop PC Dual design: Works as both a mouse when you place it on you desk and as a wireless trackball(remote) when you hold it in the air. Trackball comfort: Sculpted shape supports you hand stays in one place move the cursor without moving your arm. Wireless receiver:One tiny receiver that stays in your laptop. Smooth cursor control anywhere:Precision tracking on your desk,couch,bed or almost any other surface. For Windows or Mac OS:Control your laptop,desktop computer or home theater PC wirelessly from up to 30ft away.