Topeak Tail Lux Helmet Bike / Cycling LightExtra compact with 0.5 W ultra-bright red LED for excellent visibility. Mounts to helmet or any Topeak bag or rack with ease. Lamp: 0.5W Ultra-bright Red LED Battery: CR2032 x 1 (included) Control: 2 Modes. Constant / Blinking Burn Time: (approx) 50 hrs / 100 hrs Light Output: 4 cd Lamp Housing: Injection-molded Plastic Mount Helmet, Topeak Bags and Racks Size (L x W x H): 3 x 3 x 1.7 cm Weight: 14 g / 0.49 oz (w/ batteries) Please note the helmet and bag does not come with the light, this is for illustration purposes only