Size: 12.9*8.9*2.75cm Number of keys: 18key System requirements: Windows xPWin7/Win8/Win10, ios [Easy Setup]: Plug and play, just plug the small USB into the computer interface to use, no need to install any software. The numeric keypad works without delay and loss, and the data transmission speed is fast, which greatly improves your efficiency. [Quiet Soft Touch]: Features 18 full-size quiet keys for ease of use, great tactile feel, and precise control. [Auto sleep function]: It will automatically enter sleep mode if it is not used for 5 minutes, so you don't have to worry about wasting power. When the battery is low, the indicator light will light up to remind you, so as to avoid being unable to use when you need it most. [Non-slip Portable Design] There are four anti-slip designs on the back of this keyboard to prevent it from moving on the table and affecting your work.