The Busch & Muller Toplight 2C is a low-profile light with a big output. The two C-shaped guides spread the output from the two high-power LEDs to make the light extremely visible to drivers. The stand light feature keeps the LEDs illuminated when you stop in traffic or at a red light. A large Z reflector provides added security and visibility for exceptionally dark nights. Mounts permanently to your rear rack or carrier assembly with 50mm or 80mm bolt spacing.