A cylindrically-shaped headed item, having circular or longitudinal groove(s).
NSN 5910-00-196-2646
NSN 5855-01-134-7106
NSN 6685-00-584-7375
NSN 5990-01-617-5156
NSN 6220-01-241-4625
NSN 5999-00-225-1775
NSN 2925-01-197-7864
NSN 6150-01-320-8211
NSN 5996-01-146-5765
NSN 6150-01-296-3046
NSN 6610-00-340-2430
NSN 6220-00-116-0163