A cylindrically-shaped headed item, having circular or longitudinal groove(s).
NSN 5998-01-632-2904
NSN 5999-01-196-6839
NSN 5915-01-198-0541
NSN 6320-01-371-3047
NSN 6110-00-428-8106
NSN 5975-00-117-8139
NSN 5915-01-586-7934
NSN 6685-01-447-5633
NSN 5935-01-139-5136
NSN 6220-01-359-9969
NSN 5999-01-045-3340
NSN 5996-00-508-0383