4 Super Bright Red LED?s, 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 Seatpost (ø25.4 - ø31.6mm) * 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)