Topeak WhiteLite DX USB Rear Light (White with White LED) 4 Super Bright White LEDs 3.7V 240mAh Lithium Ion Battery 2 Modes. Constant/Blinking, Burn Time (approx) 11 hrs / 30 hrs, Reserve Time (approx) 1 hour Lamp Housing Silicon, Mount Handlebar (22.2 - 31.8 mm) Size (L x W x H) 4.5 x 4.2 x 2.8 cm / 1.8 x 1.7 x 1.1 Weight 40 g / 1.41 oz (light only)