E-Blue Cobra II 1600 DPI Ergonomic Gaming LED Mouse with Bigger Scroll Wheel (EMS151BK) Cobra II Gaming Mouse with Bigger Scroll Wheel is the Upgraded version of Cobra I Mouse High performance 'Red Wave' optical sensor provide excellent precision and control Adjustable DPI button quickly switches speed-modes 400 / 800 / 1600 (Dots Per Inch) Designers will be thrilled with it's accuracy and responsiveness so useful for Graphic Software's Multimedia Side-keys used for Fast Action Forward/Backward Web-browsing or Weapon Switch Ergonomic shape for ultimate grip designed for long hours of tension-free use Added weight increases stability and helps to enhance smooth positioning Forget about complicated drivers. You don't need them. Just 'Plug and play' All-black soft-touch shell with distinctive blue LED design Adjustable DPI (Dots Per Inch) switch 400 / 800 / 1600 4000 FPS (High Frame Rate) extremely precise tracking level High-performance optical navigation gaming 'Red Wave' sensor Micro Switch provides lifespan of up to 3 million button clicks No drivers required 'Plug and play'