MicroStream LED durable keychain light Streamlight Inc.'s 3.5" MicroStream LED key-chain light weighs just over 1 oz. and utilizes a 0.5-watt high-flux LED. Micro Optical System technology delivers 28 lumens of light and a continuous regulated runtime of 1.5 hours. Shock proof and drop-test verified, the light is constructed of machined aluminum and features an anodized finish. The unbreakable polycarbonate lens has scratch resistant coating, while a polymer body liner and shockproof switch housing allow for operation under extreme conditions. A multiple O-ring design ensures waterproof use.