(5) Leica Obturador Anillo Collar Protector para 3 3a 3b III Estándar, Cromo
Shutter ring (shutter collar, shutter guard) forLeica IIIa, IIIb. and Later typestandard. but almost of them will have a step at base(last picture). (Not use for IIIc, IIIf, IIIG).