Description: Applicable to: Notebook users; financial, banking, and workers; counter cash registers; mechanical keyboards without keyboard areas 21-key layout, Fn key combination, brown switch and blue switch for choose Ergonomic designs, Asynchronous for independent chip, free switching, no conflict with the main keyboard Plug & Play.The 2.4G signal with strong and powerful connectivity can make sure that the receiver instantly connect the keypad with computer's USB port Compare with the other standard keypad, the 21 keys extended some keys at the top, contain Esc,Tab,Back Space,and FN keys Specifications: Name: 2.4G Mechanical Numeric Keypad Layout: 21 keys Shaft Life: 50000000 times Rated power: DC3V,<5mA Support for: for Windows XPNista/7/8/10 Powered by 2Pcs AAA Batteries Colour: Black Material: ABS+PBT Size: 86 x 127 x 42mm/3.4 x 5x 1.7 inch Note: 1. Please allow slightly error due to manual measurement. 2. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! 3. Wish you a wonderful on line shopping! 4. How to Use: Step 1. Install the battery first; Step 2. Plug the receiver again and wait 10 seconds before using it; If it doesn't work, you need to rule out the cause of poor USB port contact, you can try another computer or another mouse or keyboard. Package included: 1x 2.4G Mechanical Numeric Keypad 1x User manual