The Green Light Laser Pen is constructed from durable aviation aluminum alloy with external focusing for easy adjustment of beam thickness and spot size. It features a built-in laser module with enhanced heat dissipation and circuit board protection design. Powered by a 18650 rechargeable battery for extended operation. Designed for reliable performance in cold environments; preheating recommended before use. Includes child safety lock and light touch switch for convenience and safety. Features: - Made of aviation aluminum alloy for durability - Child safety lock: turn switch to red dot and remove key to disconnect power - External focus adjustment for beam and spot control - 18650 rechargeable battery (battery not included) - Built-in laser module with improved heat sink and circuit protection - Green laser wavelength is sensitive to environmental conditions; optimal in cold climates with preheating Specifications: - Material: Hard aluminum - Surface treatment: Anodizing - Switching mode: Light touch switch - Wavelength: 532nm - Start-up time: 0.001 seconds - Working voltage: DC 3.7V - Dimensions: 22 x 158mm - Battery: 18650 rechargeable battery (not included) Package included: 1 x Laser Pen (Battery not included)