Work easily day or night with this illuminated rechargeable keyboard that automatically adjusts to brightness in room. The illumination can also be adjusted to five levels manually. Back-lit keys provide precise illumination of laser-etched characters, rather than the entire key, for less distraction. Hand proximity detection turns illumination on or off when hands approach/depart keyboard area. The PerfectStrokeâ„¢ key system and Incurve Keysâ„¢ are uniquely designed to combine the comfort of traditional keyboards with the smoothness and fast response of laptop keys. The result is whisper-quiet, comfortable typing on this full-size keyboard. The sleek and streamlined keyboard stands upright when not in use to conserve desk space. Keyboard has built-in rechargeable batteries using a micro-USB cable to eliminate disposable battery waste; on/off switch conserves battery power. The powerful long-range Unifying receiver virtually eliminates delays and dropouts, is small enough to stay plugged in to the computer's USB port, and supports both keyboard and compatible mouse. The keyboard automatically pairs to your PC for a fast, reliable connection right out of the box.