Locking nut now has embedded rubber O-ring to help prevent loosening. Can use end cap A8CAP, rubber end plug BP16, or fighting butts F2M, F2 and F5. Includes: 1 ea. threaded barrel, locking nut, fixed hood and sliding hood. Threaded Barrel O.D. - 0.750" Fixed Hood O.D. - 0.985" Length - 41.3mm (1.626") I.D. - 15.7mm (0.620") *Note item is shown with insert.