?Worry-free Guarantee?: T-DAGGER promises 18 MONTH AFTER-SALE SERVICE ( return for a new one or full refund).PLZ contact us if there exists any problem with the mouse.T-DAGGER is conmmitted to satisfy your needs.HOW TO CONTACT US 1. CLICK OUR STORE NAME "T-DAGGER-US" 2.CLICK THE "Ask a question". ?Wide Compatibility?T-DAGGER wireless gaming mouse, work perfectly for Windows 7/8/10/XP/Vista/me/2000/Mac10.X, etc. For Mac OS, side buttons are not available.(USB receiver is beside the battery compartment .). ?Advanced Energy Saving Mode?To save energy, the wireless computer mouse will enter sleep mode if it is NOT used after 8 minutes, just press any button to wake it up. The bottom button also can be used to control the mouse’s light on/off or switch on/off. ?5 DPI Levels for Gaming and Work?Wireless gaming mouse can be driven from 4000-2400-2000-1500-1000 DPI, providing excellent sensitivity and precise tracking on a wide range, ideal for gaming and daily work. ?Cool LED Backlights?Mouse for gaming provides a RED LED backlit, greatly matching your cool style and creating a great atmosphere to enhance your gaming fun. Besides, gaming mouse will make your gaming room more special, especially at night.(Light is disabled). ?Silent & Durable Click?Gaming mouse will make no noise when clicking left or right buttons, no worry for disturbing others. Suitable for public places such as office, library dormitory, cafe, etc. Our wireless mouse is tested for up to 5 million clicks.