<ul><li>SPECIFICATIONSModel: FuDe 1361Type: Wireless SilentConnection: 2.4G HzErgonomic Design: SymmetricSensor: Invisible OpticalResolution: 1600 DPIReport Rate: 250HzButtons Number: 3Power Source: AA BatterySMALL MOUSE ON/OFF BUTTONSystem Requirement: Windows XP/7/8/20,Mac OS X10.8+THIS IS A BRANDED STOCK LOT PRODUCT SO THERE WILL BE LIGHT MARKS ON IT. ALL PCS WORKING FINE.IF YOU WANT TO SEE ORIGINAL PICTURE CHAT WITH US ON DARAZ CHAT. THANK YOU......!</li></ul>