NAP Killzone Crossbow Broadhead 100 Grain 2 Inch Cutting Diameter Three Pack 100 grain, 3 pack 2 inch cutting diameter Spring Clip design - no 0-rings or rubber bands Heavy-duty, razor-sharp .039 inch blades Designed for Use out of crossbows up to 400 FPS Features patented "Spring Clip" blade retention system to keep blades closed in flight 2" cutting diameter for devastating wound channels & excellent penetration Heavy-duty, Razor-sharp .039" blades Designed for use out of crossbows up to 400 fps