Cryogenic hydrogen ground coupling used to fill the Apollo CSM's hydrogen tanks pre-launch, measuring 10″ long with a diameter of 3″, marked on the side: "Coupling, Ground, Fill, H2, PN 64-022, Serial No. 0001, Contract No. NAS 9-150." This coupler would mate with a corresponding Service Module side coupler during pre-flight operation, with disconnect occurring upon retraction of the launch pad swing arms shortly before lift off. In fine condition.
Terms and abbreviations used in our descriptions.