E-Element E1070 2.4G Wireless Optical Mouse, 15 Month Battery Life, 3 Adjustable DPI Levels (Black) 2.4G wireless technology keeps the connection stable at distances of up to 10m Auto detect to Nano receiver No need to pair with receiver Infrared technology ensures smooth track over a variety of surfaces CPI switchable: 1600-1200-800 Long battery lifetime up to 15 months with 1 AA battery,Battery NOT included