The PRO III 12" L-850A,B RCL/TDZ light does double duty as a runway centerline light and touch-down zone light. The RCL is a bidirec-tional light, typically clear/clear or clear/red, with two 48 W lamps. The TDZ is a clear unidirectional light, with a 48 W lamp. RCL/TDZ may be used for any category FAA or military runway.