RAPOO EV250 Ergonomic Vertical Wireless Mouse 6 Buttons 800/1200/1600 DPI Optical Silent Click Mice - Black Main Features_ 60° degree angle unique design, Ergonomic vertical mouse EV250 2.4GHz wireless optical sensor,Max support 10 meters stable connect. Silent click design This is a wireless noiseless mouse,help you create a quiet working environment. 3 Levels Adjustable DPI,one key switching Buttons_ Left/Right, Forward/Backward, DPI, Scroll Wheel (middle button) Wireless Version Resolution_ 800-1200-1600 DPI Adjustable High-end Surfree invisible engine Surfree invisible engine makes your mouse move freely on almost all surfaces. 9-month battery life With Rapoo's latest energy saving technology and power switch, you can use your mouse without power interruption for up to 9 months. System Requirements_ Windows XP/Vista/7, Windows 8/10, with USB port. Buyer Notice_ Battery Not Included Power Supply_ Battery Package weight_ 0.1520 kg Package size (L x W x H): 12.50 x 8.50 x 8.00 cm / 4.92 x 3.35 x 3.15 inches Package Contents_ 1 x Mouse, 1 x Nano Receiver, 1 x User Manual