Bornd 2.4GHz Optical Wireless Mouse, White (E220 WHITE) US Cypress RF Chipset 8 years battery life with normal use Auto Sleep/Awake button to save power Cellular technology, multipoint interconnection (many connection technologies compatible with Bornd wireless mice and keyboards) Press the Left and Right buttons at the same time for 3 seconds to adjust resolution between 1000 & 2000 DPI Power saving function is set-up automatically every 8 minutes and is easily activated