Color: Mainly black， with two patterns - blue/red words &amp; icons (patterns of the item will sent by random， thank you.)<br />Number of Key: 49 <br />Working Range: 10m <br />Frequency Band: 2.4 - 2.4835GHz unlicensed ISM band <br />Receiving Sensitivity: -75dbm (standard) <br />RF Output Power: 4dbm maximum <br />Operating Distance: 0 - 10 m <br />Bluetooth Version:3.0 <br />Uninterrupted use time:80 hours <br />Spare time: 10 days. <br />Charging Time: 3 - 4 hours <br />Powered By: Built in rechargeable Li-ion battery， USB port <br />Compatible with one of the following OS : <br />Nokia Symbian S60(V3.0 &amp; later) <br />Apple iPhone 4.0 <br />Microsoft Windows Mobile (V6.0 ; later) <br />Windows XP/Vista/Win 7(with IVT stack/Broadcom) <br />Mac OS <br />Linux OS <br />A perfect item for computer home use &mobile use <br />Ideal for typing emails， chat， and playing games <br />Pocket size， sleek and slim design <br />Extended battery life for hours of typing <br />49 responsive， accurate standard QWERTY keys lay out <br />Convenient， portable ; easy to use