A cylindrically-shaped headed item, having circular or longitudinal groove(s).
NSN 5996-01-513-2521
NSN 6320-00-937-5625
NSN 6645-01-150-9847
NSN 4140-00-483-1932
NSN 7035-01-378-9325
NSN 6110-01-177-5988
NSN 5990-01-136-4068
NSN 6645-01-540-0231
NSN 5999-01-096-2540
NSN 5975-01-538-6114
NSN 5985-01-205-7526
NSN 5910-00-355-6328