4" long body with 2 locking nuts. Can use end cap A8CAP, rubber end plug BP16, or fighting butts F2M, F2 and F5. Completely assembled except for end cap. Threaded Barrel O.D. - 0.750" Fixed Hood O.D. - 0.985" Length - 102mm (4.000") I.D. - 15.7mm (0.620")