A cylindrically-shaped headed item, having circular or longitudinal groove(s).
NSN 6620-00-613-3023
NSN 5965-01-423-8543
NSN 5905-01-438-1832
NSN 5935-01-425-8184
NSN 5905-00-661-2395
NSN 2925-00-585-9861
NSN 6130-01-042-6870
NSN 5855-00-256-5562
NSN 6130-01-228-8062
NSN 5996-00-179-9583
NSN 5855-01-429-8702
NSN 6220-01-036-5690