Check the listing for details. Replacement O-rings, Swhacker Mechanical Broadheads, 100 Pack. Color: Black, Condition: New. Listed at 4.99 USD. Replacement O-rings, 100 pack Drop-in replacement O-rings for all models of Swhacker broadheads. These O-Rings also fit the Rage two blade “Legacy” broadheads. Replaces heat shrink bands, eliminating the “Bic lighter” step. With two bladed broadheads, often remains intact on the arrow shaft after the shot. Superior weather resistance All questions typically answered in less than 24 hours. Condition is New. Shipped with USPS First Class. NOTE: The swhacher broadhead is designed to expand in the soft flesh of the deer after clearing the skin and the rib cage. As this is not accurately represented in a dense foam target, a cardboard box, open end toward the target, was placed in front of the target to allow expansion. The arrows consistently expanded after clearing the single layer of cardboard on the box. Testing was performed with 100 grain broadheads, with an arrow velocity of 211 FPS. The O-rings weigh less than 1 grain (A quantity of 25 on my powder scale weighs about 14 grains). The cardboard box was intentionally shot in different areas, to prevent the broadhead tipped arrows from damaging each other.