... Optical sensor * Retractable usb line* Dimensions: 8,1 x 4,8 x 1,65 cm * Colours: white, black, etc.SPECIFICATIONS2.4G wireless mouse ... technology,plug and play,and don't need any setting for connecting*power-saving design*advanced 2.4GHz wireless technology*16 ... automatically switch and adaptive frequency*Have passed CE/FC/WEEE ...