Not all rifle owners choose to use our world renowned push button swivels on their firearms. Many appreciate the classic lines of a rifle with time honored, traditional swivel studs holding their favorite sling. But the one thing they don’t like is having is the interference of that swivel stud when shooting over a sandbag rest or a sling getting in the way and taking up space when the rifle is stored in a safe. Our brass inserts are for a removable stud. Fits a 3/8" 10-32 thread machine screw.