the laser transmitting module emits a small intense beam of wavelength (? ) 650Nm (colour: red on visible spectrum). It can be used in various applications like laser obstacle, laser guitar, home-made laser tag, etc. The module is compatible with various contemporary microcontrollers including Arduino, raspberry pi, etc. It is available with a fixed screw hole for easy deployment. Specifications: supply voltage: 5v dc. Output wavelength: 650 nm. number Of pins: 3 (gnd, vcc, i/p). Dimensions (lbh in mm): 20 x 5 x 13. Package include: 1 x 650nm laser diode pcb / module.