This is a 650nm 6mm 6v 5mW Laser Dot Diode Module Head Red. The laser head is composed of a light-emitting tubecondenser lens and adjustable copper sleeve and it is assembled when deliveredthe focal length of the lens is adjusted glued by strong glue stickwhich can work directly after connecting to a 5V DC power supply.The laser head is composed of a light-emitting tubecondenser lens and adjustabl...