The Proton Pro is designed and engineered to the highest standards. It is only about 3.5 inches long but offers a 115 lumen brilliance in white mode and a 12 lumen brilliance in red mode. Waterproof aluminum case features positive on/off and glow-in-the-dark seal. Works with any AA battery. 24k gold contacts with lifetime warranty. Wt: 1.6 oz.