Product Description Brand Name: Rapoo Origin: CN(Origin) Type: Bluetooth Wireless Certification: CE Certification: EAC Number of Rollers: 1 Gross Weight: 60g DPI: 1300 Package: Yes Number of Buttons: 3 Operation Mode: Opto-electronic Style: 3D Style: Finger Style: Trackballs Power Type: Battery Model Number: 3500PLUS/M200PLUS Hand Orientation: Both Hands Interface Type: USB