. PN: 920-009206 Mouse: Sensor technology: High Precision Optical Tracking Sensor resolution: 1000 dpi Number of buttons: 3 Scroll wheel: Yes- Mechanical Scroll Buttons: Middle Button Unifying ready mouse: No Unifying ready receiver: No Battery life Mouse: 18 months Battery type mouse: 1xAA Keyboard: Battery life Keyboard: 36 months Battery type keyboard: 2xAAA Wireless operating distance: 10 m 4 Wireless technology: Logitech Nano Receiver Package Contents: Keyboard 2 AAA batteries (pre-installed) Mouse 1 AA battery (pre-installed) USB receiver User documentation https://www.logitech.com/en-hk/product/mk470-slim-wireless-combo