Manufactured from 6AL4V titanium, the SRS Lever Action Brake is designed to be used on the Ruger Marlin Trapper and the Henry Lever Action X models. We offer bore sizes for 30-30 and .45. Threads are 11/16-24 for the Marlin and 5/8-24 for the Henry. These weigh in at a scant 2.0 oz, and are .990” OD, and 2.5” OAL. The 3 port design greatly reduces felt recoil and makes shooting your rifle a breeze. These are a self timing brake and they have a timing nut that tapers close to the barrel diameter.