This set consists of four complete, super detailed early exhaust assemblies. The first B-1Bs were fitted with turkey feathers covering the exhausts. Early in the program, it was found that vibration problems were splitting and breaking them, so they were removed from all subsequent Bones. This set contains rear engine faces with flame holders, exhaust tubes and covered exhaust nozzles, and allows you to build a super detailed early B-1B. Quick and easy to install with simple, clear instructions. For the Revell B-1B kit.