These replacement shrink bands secure the blades on 100-grain, 1.75-inch and 2-inch 3-blade Swhacker broadheads (and crossbow models), made of flexible, military-grade plastic that won’t stretch or rot. To install, a band is placed over the tip with the blades fully enclosed, then slid down the ferrule into the retaining groove; if it doesn’t seat, gentle heat from a lighter or hair dryer shrinks it into place. Sold 18 to a pack.