Laser laser bluetooth projection keyboard

Keyboard layout: QWERTY layout (about 20MM spacing)
Light source: red laser
Projection size: width: 250MM, height: 100MM
Working platform: non-reflective, opaque plane
Recognition rate: 350 characters/minute
Battery and capacity: Li-ion battery 550MAH(MAX) @ 3.7V
Battery working time: about 120 minutes
Battery charging time: about 120 minutes
Charging power supply: USB input/5V 1A
Bluetooth: V3.0, HID PROFILE VER 1.0
Frequency range: 2402 2480MHZ
Channel: 79
Modulation method: GFSK
Size (mm): 76MM X 19MM X 25MM
Weight (g): about 50g