The TK50 R5 LED Flashlight by Fenix is their first to run on D batteries. This flashlitght is powered by two D batteries and has four different brightness levels as well as three typs of flashing modes--strobe, SOS, and warning flash. It can put out 255 lumens on the highest setting or run for 480 hours on the lowest setting. This flashlight has an IPX 8 waterproof rating and a durable Type III hard anodized finish. Built for the outdoors or as an everyday light for home needs, this flashlight has dual button side switches for easy operation. Get one for your house and one for your outdoor adventures. Features and Specifications: Uses Cree XP-G R5 LED with a lifespan of 50000 hours Uses two 1.5V D (Ni-MH, Alkaline) batteries 228mm (Length)?39mm (Diameter)?60mm(Head) 233-gram weight (excluding batteries) Digitally regulated output - maintains constant brightness Reverse polarity protection, to protect from improper battery installation Two side button switches, easy operation Made of durable aircraft-grade aluminum Premium Type III hard-anodized anti-abrasive finish Toughened ultra-clear glass lens with anti-reflective coating Notice: The above-mentioned parameters (tested in lab using quality D alkaline primary batteries) are approximate and may vary between flashlights, batteries, and environments.