A cylindrically-shaped headed item, having circular or longitudinal groove(s).
NSN 6240-00-151-5382
NSN 5990-01-294-6198
NSN 5915-01-196-9620
NSN 5950-01-485-0246
NSN 5920-00-066-6885
NSN 4140-00-237-5797
NSN 5960-01-081-7745
NSN 5975-01-347-0481
NSN 5965-01-532-2112
NSN 6220-01-585-0639
NSN 5855-00-631-4565
NSN 6645-01-172-6838