RCBS is known for making high-quality reloading equipment. Their shellholders are no different, they are made from high quality steel and will fit virtually any single stage reloading press.
221 Remington Fireball
222 Remington Magnum
7mm TCU (Thompson/Center Ugalde)
These shell holders are also used with the RCBS Hand Priming Tool part # 90200 and Automatic Priming Tool part # 9460.