Plug and Play: No regulatory training required Transmission: wireless, fast and sensitive, up to a range of 10 meters. Supports automatic hibernation mode, no power button is required. Slim and compact: number pad, wireless 18 keys, very convenient and portable. The red light is on when the device is ready for data entry. Battery: One AAA battery (not included) for the keyboard to work. Product Description Size:BT This is a simple numeric keypad, which can only be used by USB Y-through receivers and ensures that the device is also free from transport length wires and chains. A distance of 10 m is acceptable for the secure connection. By the way, it is energy saving with automatic hibernation mode. All in all, it's a perfect company for travel needs for a handy and portable textured design. Specification: Material: ABS Number of keys: 18 keys Connection: 2.4G Voltage: 1.5V Size D & 39; Item: 8.5*13.8*2.2cm/3.35*5.43*0.87in(L*W*H) Weight D & 39; Item: 76g/2.7oz Package size: 14.8*9.3*3.5cm/5.83*3.66*1.38in (L*W*H) Package Weight: 100g / 3.53oz Package List: 1*NUMERIC KEYBOARD 1 * USB Receiver