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 power.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 Ktransmission rate parity bit: no paritydata bit: 8nterface: 3.0 v TTL signal2 ma of electric flow: DC3V, standby, measure 120 maLaser type: 635nm, 1 mw. (Red)Range: 0.3 to 50 metersmeasurement speed: 0.3-3 stypical precision: +/- 1mmstorage temperature: -20-60 Celsiusoperating temperature: -10-40 CelsiusColor: BlackMaterial: ABSSize: 45 * 25 * 12mmPackage Contents:1 X Laser range finder sensor1 x english Instruction manualOnly 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.