The num lock function is independent of any other keyboard that are currently connected.The mechanical switch keypad can ensure 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.Applicable models: generalType: Numeric keyboardNumber of keys: 21 (keys)Switch: brownWhether to support plug and play: supportConnection with computer: wiredWhether there are multimedia function keys: noneShortcut key: noneDo you have hand rest: NoWaterproof function: does not support waterproofKey technology: mechanical shaftBacklight function: support backlightWhether to support ergonomics: supportLine length: 1.5 (meters)Luminous: whitePressure feeling: 45g +/- 20gStyle: weakBacklight mode: 3 typesBrightness adjustment: 6 levelsSuitable for: notebook users; financial, banking and securities workers; counter cash registers; mechanical keyboards without keyboard areacolour:WhiteMaterial:ABS+PBTSize:12.3 x 8.2 x 4.2cmPackage Contents:1 x Digital Mechanical KeypadOnly the above package content, other products are not included.Note: Light 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.