A cylindrically-shaped headed item, having circular or longitudinal groove(s).
NSN 4140-01-643-1899
NSN 6240-00-426-1972
NSN 6105-01-512-9862
NSN 5975-00-370-0401
NSN 5915-01-406-4637
NSN 5965-00-335-0305
NSN 5985-01-206-3746
NSN 5945-00-251-7812
NSN 4140-01-437-5964
NSN 5985-01-455-0321
NSN 4140-01-152-1214
NSN 2925-01-255-6394