feature: drum style 1: 2.4GHz wireless connection (USB receiver) 2: 2 x AAA battery version (not included) 3: Ergonomic design to relieve and prevent carpal tunnel syndrome. 4: Optical laser technology, precise control 5: Easy to use, comfortable to hold, prevent mouse hand. 6: L / R mouse buttons, 2 thumb buttons, and a clickable scroll wheel, 2 dpi buttons (dpi + / dpi -). 7: You choose the hand position that best suits you. Plug and play, compatible with Mac. Specification: 1: Item Type: Ergonomic Optical Mouse 2: Resolution: 800dpi; 1600dpi; 2400dpi. 3: Buttons: 4 buttons and 1 wheel (middle button) and 2 dpi (adjustable) 4: Maximum working range: 10m 5: Color: Black + Red 6: Material: ABS 7: Button life: 5 million times 8: Power: 2 AAA batteries (batteries not included) 9: System requirements: Windows 98 / Me / 2000 / XP / Vista / Win 7 / Win8 / win10 or latest. 10: Product size: 10 * 8.5 * 7cm 11: Item weight: 80g (including USB receiver weight) 12: Package size: 12.2 * 8.7 * 8.3cm