Custom fore end swivel base screws into barrel lug on most Ithaca 37’s Ithaca 87’s Deerslayer DSPS and M&P models with regular and extended magazines. Other 37’s may require drill and tap. Also includes 3/4 rear swivel stud and one pair GT Locking Swivels. – GTSW-26 1 Loops Black-Oxide Finish