Specifications: Color: BlackOperation frequency: 2.4GHz RFOperation distance: up to 10 metersOperation voltage: 3.3VOperation current: <300mASleep current: <1mASystem requirement: Windows 2000/Windows XP/Windows Vista/Windows CE/Windows 7/ Linux(Debian-3.1 Redhat-9.0 Ubuntu-8.10 Fedora-7.0 tested), Android OS Devices (with standard USB interface)Battery type: 2 * AAA Battery (not included)Item size: approx. 12 * 3.7 * 2.7cm / 4.7 * 1.5 * 1.1inItem weight: 40g / 1.41ozPackage size: 18 * 9 * 3.5cm / 7.1 * 3.5 * 1.4in Package weight: 75g / 2.64oz