This green light laser pen is made of durable aviation aluminum alloy with child safety lock. It is externally focused and has an adjustable light column and spot size. The 18650 rechargeable battery provides long battery life. The built-in laser module improves heat sink and has circuit board acquisition and protection design. Suitable for use in cold environments, need to preheat. Start-up time is less than 0.001 seconds. Dimensions are 22x158mm. Package includes 1 Laser Pen. Battery not included. Features: Made of aviation aluminum alloy, it is durable and has a child safety lock. When not in use, turn the switch key to the red dot and pull it out to disconnect the power. External focusing, easy to adjust the thickness of the light column, spot size, 18650 rechargeable battery, large capacity, long battery life. Built-in laser module to improve the heat sink, circuit board acquisition and protection design, green light is greatly affected by the climate, suitable for use in cold environments, need to put pockets to preheat. Specifications: Material: hard aluminum Surface treatment: anodizing Switching mode: light touch switch Green wavelength: 532nm Start-up time: 0.001 seconds Working voltage: DC3.7V Dimensions: 22x158mm Battery: 18650 rechargeable battery (not included) Package included: 1 x Laser Pen (Battery not included)