Set includes Bushing Full Length Sizing Die, Bench Rest Ultra Micrometer Seater Die and 3 bushings. The Bushing Full Length Sizing Die offers advanced precision by allowing you to precisely control the amount of neck sizing tension in your reloaded brass while sizing the body and bumping the shoulder. This die improves accuracy and prolongs case life because the case’s shoulder and body is sized down just enough to fit in a minimum-sized SAAMI rifle chamber, and bushing limits working of the neck.