Solidtek IR Wireless Ivory USB Keyboard w/ Built in Trackball Wireless input with built-in infrared technology. 88/89 keys with embedded numeric keypad and 12 dedicated function keys. Switch travel: 3.1 +/- 0.3mm Switch life: 5 million life cycles Dimension : 13.31(L) x 5.58(W) x 1.10(H) INCH