Muzzy Broadheads - 6 Pack are screw in broadheads. Muzzy Broadheads have become legendary for their Bad To The Bone dependability and true flight. It begins with the hollow ground design of Muzzy Trocar tips, which are responsible for the exceptional penetrating power through both flesh and bone. Razor sharp stainless steel blades interlock within the body of Muzzy Broadheads forming a column of steel that adds support to the aircraft aluminum bodies. You can't go wrong with Muzzy Broadheads. Popular ultra-lite Head. 1-3/16 inch cutting diameter and .020 inch thickness. They are BAD TO THE BONE!