Ruger Mini-14 Recoil Reducer (Blued Steel 1403B)
Pins on, Nickel steel version shown above . 4" long, .875" diameter. Masen 1403. There are two models of blued steel versions to choose from. M1403B For Mini-14s that were manufactured 2004 and earlier, and M1403BB for Mini-14s manufactured 2005 to present.