A cylindrically-shaped headed item, having circular or longitudinal groove(s).
NSN 6110-01-090-0804
NSN 6650-00-084-4258
NSN 6685-00-044-3078
NSN 5965-01-524-5310
NSN 5960-01-235-8941
NSN 6220-00-873-6261
NSN 2925-01-602-8709
NSN 5920-01-020-7659
NSN 5910-00-434-9715
NSN 5985-01-136-0199
NSN 5960-01-346-6002
NSN 6135-01-390-7364