No doubt about it: Forster Bench Rest dies set the standard for quality and precision. That's why they're the first choice of some of the world's toughest reloading critics including members of the US Marines US Navy Seals US Army Rangers US Secret Service and the US Olympic Shooting Team. This set includes a Full Length Sizing Die and a standard Bench Rest Seating Die made with the superior manufacturing quality that is a proud Forster tradition. "S" (Standard) Jaws are factory installed and ready for reloading. *Note: If you are using the Forster Co-Ax Press then a Shell Holder Jaw is not required. If you are using a non-Forster Co-Ax Press then use the Shell Holder recommended by the manufacturer of the press being used.Shell Holder Jaw "S" / Item Number FRS001231 / Small End Holds: .343" to .422" rim / Large End Holds: .468" to .562" rimShell Holder Jaw "LS" / Item Number FRS001251 / Small End Holds: .312" to .375" rim / Large End Holds: .531" to .625" rim