Microsoft Wireless Comfort Desktop 5050 (PP4-00001) Ergonomist-Approved Comfort Curve Design ; Designed to fit your right or left hand Advanced Encryption Standard (AES) 128-Bit Encryption Built in palm rest helps support and straighten wrists and 4 AA alkaline battery Wireless for increased freedom. System requirement is windows 10 / 8 / 7 and mac os x v10.4  10.7 Customizable shortcut keys to easily access your favorite programs Works on virtually any surface with BlueTrack Technology Ambidextrous design is suitable for use with either hand Refer user guide below.