All Kirby Morgan Helmets except the SuperLite 17B.
560-074 Bottom Ring, 560-517 Stainless Steel Helmet Shell,
All shells with Bottom Ring Assemblies: 505-105, 505-106, 505-107, 505-108, 505-162.
All Kirby Morgan Helmets and BandMasks® with Tri or Quad Valve Exhaust Systems, excluding the KM 47 fiberglass helmet and the KM 77 stainless steel helmet.