Model Number: SK-M590 Brand Name: Skull or OEM Key Specifications/Special Features: 1 Resolution: 1000/1600dpi2. Buttons: 3 keys3. Accessory: Nano receiver, plug-and-play function4. Battery type: 2*AAA5. Working frequency range: 2402 to 2480GHz6. Effective range: 10m7. Anti-slipping in virtue of long time operating8. Power supply will be automatically cut-off when the receiver is taken off9. Compatible with Microsoft's windows 98, SE, 2000, NT, XP, Vista and WINS 7, 1010.Product size:99*57*38mm