[OLED Screen and Intuitive Parameters Display] The OLED screen is on the top of the mouse, displaying key status including DPI, battery level, connection mode and status, let you always know your current mode and status as well as exactly how much battery power is left [Unique Ball-shaped Thumb Wheel and Exchangeable Back Cover] Work efficiency with thumb controls for horizontal scrolling, easy to roll horizontally and quickly. Roll up to move to the left, roll down to move to the right, it can be used in WPS, web browsing, etc. (Office software need to download a upgrade driver for use). Hollowed-out honeycomb cover and ABS normal cover are offered, choose one that suits you according to different needs. The back shell is easily removable for cleaning [Ergonomic Vertical Design] Vertical mouse with comfort shape and smooth lines reduce arm discomfort and hand stiffness. Removable palm rest let your forearm and mouse to be a whole part and make you wrist