This tail lamp is equipped with two installation methods, which are convenient for you to install it on the seats or the seatpole according to your needs. Powerful functions making your night riding safer. Features: When the brake is detected, the tail lamp highlights for 3 seconds. When going downhill, the chip automatically corrects the angle according to the algorithm to ensure the accuracy of brake sensing. When the light is dim, the tail light will automatically light up when the bicycle is moved If the bicycle is not moved within 30 seconds, the tail light will automatically turn off. High brightness, 180 degrees wide angle visible. The brake-warning light will be activated after passing the large pit and the shockbelt. The brake-warning light will not be on for a long time when the bike swings left and right and passes through a small bumpy road. Free adjustment of 6 modes. IPX5 waterproof, no fear of rainy day. USB rechargeable design and large capacity battery, you don't need to worry its battery. With power indicator for timely recharging. Specifications: Item color: black Light color: red Waterproof: IPX5 Material: aluminum alloyandplastics Battery: 3.7V, 420mAh Package size: 90 x 60 x 45mm or 3.5 x 2.4 x 1.8in Package weight: 73g or 2.6ounce Packing List: 1 x Bike Tail Light 2 x Belt 1 x USB Cable 1 x Bracket 2 x Antiskid Rubber Pad 1 x User Manual Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.