This is a laser diode module that can be directly driven by two 1.5V batteries connected in series. It can be used as various marker devices. All units have been tested and confirmed to work, but there may be slight variations in brightness. ◆Specifications 　Light output: 5mW 　Supply voltage: 3VDC 　Lead wire polarity: Red → +, Blue → - *The unit will be instantly destroyed if the polarity is reversed. 　Operating current: 25mA or less 　Wavelength: 650nm (Red) 　Spot shape: Dot 　Operating temperature: -36 to 65°C 　Operating life: 1000 hours or more 　Dimensions: φ6mm x 13mm (excluding lead wires) 　Lead wire length: Approximately 50mm ◆The lens has a structure as shown in the photo, and the focus can be adjusted by rotating the tip. ◆This is a set of 5 units.