*2.4G WIRELESS *SILENT BUTTON *WATERPROOF DESIGN *PLUG NAD PLAY *AUTOMATIC SLEEP DESIGN *ALUMINUM ALLOY 3D NON - SLIP ROLLER *MIRROR GRADIENT DESIGN *FRONT SIDE MICRO CHARGING INTERFACE DESIGN As quiet as the button is quiet Two color injection molding process without wear Clear without pollution for a long time without discoloration Automatic sleep power saving technology Multimedia shortcut key design Plenty of batteries last long on charge