A cylindrically-shaped headed item, having circular or longitudinal groove(s).
NSN 5990-00-284-0537
NSN 5930-00-624-8418
NSN 5950-01-535-0099
NSN 6110-01-649-3390
NSN 5930-01-380-9866
NSN 6650-00-276-9838
NSN 5990-01-565-2226
NSN 5945-01-115-8091
NSN 6645-01-544-9475
NSN 6220-01-188-0135
NSN 6135-00-112-8637
NSN 5910-00-518-4608