The num lock function is of any other keyboard that are currently connected.The mechanical switch keypad can a fast response. Compare with the other standard keypad, the 21 keys extended some keys at the top, contain Esc,Tab,Back Space,and FN keys. Mechanical numberic keypad has 3 backlight model and 6 backlight brightness can be adjusted. By simultaneously pressing the FN key and another key, you can change the backlight and brightness. Keyboard Connection:WIRED Type:ERGONOMIC Interface:bluetooth Brightness adjustment:6 levels Backlight mode:3 types Style:weak Pressure :45g +/- 20g Luminous:white Line length:1.5 (meters) Whether to support ergonomics:support Backlight function:support backlight Key technology:mechanical shaft Waterproof function:does not support waterproof Do you have hand rest:No Shortcut key:none Whether there are multimedia function ke:none Connection with computer:wired Whether to support plug and play:support Number of keys:21 (keys) Type:Numeric keyboard Applicable models:general Suitable for: notebook users; financial, banking and securities workers; counter cash registers; mechanical keyboards without keyboard area Size:12.3 x 8.2 x 4.2cm color:White Material:ABS+PBT Package Contents: 1 x Mechanical Numeric Keypad Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.