The Anti-Fog Kit consists of a retro-fit lens that you attach to the front of the beam face and a single reflector. Both these items feature a special nano-coating that prevents condensation from forming. Condensation can be a problem in some unique environments where warm air meets a cold surface and the beams were unable to differentiate between this and smoke. Previously this would have resulted in a false alarm, but this Anti-Fog Kit eliminates this possibility in condensation prone environments.