function: send capital letters "O" to open the laser, capital letters "C" to close the laser, capital letters "D" to measure distance, capital letters "S" to display the module temperature and . Instructions: open the laser, laser, a single measurement, get to the supply voltage and the temperature. Profession laser serial module Design and development. communication interface: serial communication (TTL), 19.2 K transmission rate parity bit: no parity data bit: 8 nterface: 3.0 v TTL signal 2 ma of electric flow: DC3V, standby, measure 120 ma Laser type: 635nm, 1 mw. (Red) Range: 0.3 to 50 meters measurement speed: 0.3- typical precision: +/- 1mm storage temperature: -20-60 Celsius operating temperature: -10-40 Celsius Color: Black Material: ABS Size: 45 * 25 * 12mm Package Contents: 1 X Laser range finder sensor 1 x english Instruction manual Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.