6000 Series machined aircraft aluminum with anodized finish. Tempered glass lens, o-ring sealed. C4 LED technology, impervious to shock with a 50,000 hour lifetime. High for maximum illumination: 850 lumens; 10,000 candela; 200m beam; runs 1.5 hours. Medium for bright light and longer run time: 350 lumens; 4,000 candela; 126m beam; runs 4 hours. Low for a less intense beam and extended run time: 85 lumens; 1,000 candela; 63m beam; runs 12 hours.