QUALITY PCB AND WATERPROOF: Efficient circuit, support higher output, prevent from over-heating, passed thousands of waterproof testing. 3-MODE SWITCH: High output + Low output + Strobe - Suitable for various use. High output for careful working, low output for playing, stroble for emergency. LIGHT WEIGHT AND HANSFREE: Zoomable angle adjustable design. Light weight & comfortable to wear: Best strap on head lamp on market for civilian use, convenient and hands-free to use.