The ROCKBROS A54BK is a rear bicycle light designed to keep you visible and safe during your rides. It features an LED light source with six different modes, including constant high and medium beams, slow and fast flashes, pulsations, and an economic setting to help you manage your visibility based on the environment. Built from durable plastic in a sleek black finish, the light is powered by a 500 mAh battery that provides up to 6 hours of runtime and recharges via a micro USB port. Its IPX5 waterproof rating ensures it continues to function reliably even when you are caught in the rain. For installation, the device uses a flexible, rotatable mounting bracket that allows you to secure it firmly under your saddle for the best possible angle of visibility.