... 1, lock→the mouse on/off; 2, Home→ keyboard :Home key; 3, Menu→ keyboard :F1 key; 4 ... system volume reduced key; How to use 1,how to use receiver: connecting the receiver to the USB interface, the computer ... ok. Do not need to install for the second use. 2, mouse on/OFF function: LED work, ... . For incoming materials, sampling observation proportionally based on the material character 3. In PCBA process, ...