Amazingly small unit projects laser keyboard onto any non-reflective surface, and detects when the virtual keys are "touched". Provides both standard USB HID keyboard connectivity and non-standard Bluetooth SPP connectivity (requires Celluon driver on target platform to receive keystrokes). The CL850 can be powered by USB, with included AC adapter, or with built-in lithium ion battery power. Charge battery before use. Works via USB with any computer than can supply sufficient power (does not work with iPad for power reasons). Bluetooth compatible with Windows XP/Vista/Win7 using Microsoft Bluetooth stack, and some older mobile platforms. See celluon.com for list of compatible drivers. We recommend installing drivers on your phone or PC to confirm compatibility before purchase. Keyboard Project Specifications: 1. Light source - Red laser diode. 2. Keyboard Language - English 3. Keyboard layout - 19mm sized QWERTY layout. 4. Keyboard size - Approx. 304mm*105mm. 5. Keyboard position - Approx. 100mm from keyboard device. 6. Projection surface - Non-reflective, opaque flat surface. 7. Keystroke Sound - Built in buzzer (Mute on/off the sound). 8. Visibility - Visible in 1000-5000 lux ambient light. Keyboard Sensor Specifications: 1. Illumination - Visible in incandescent light of 1800 lux. 2. Detection rate - Over 400 characters per minute. 3. Effective key stroke - Approx. 2~5mm. 4. Operating surface - Any flat surface. Electrical Condition Specifications:1. Power source - The USB bus power. Lithium ion battery power. The DC input power. 2. Battery capacity - 830mAH(Max)@3.7V. Replaceable soft-pack type. 3. Adapter - Rating 1A @ 5V. 4. Interface - USB 1.1 and 2.0 for PC. Bluetooth(v1.1 class 2) for Mobile devices. 5. Touch Switch - Switch the active/Standby mode manually. 6. Power consumption - max. 3W@5V.