New Archery Products Thunderhead 3-Blade Expandable Broadheads - 5 Pack - The sharpest blades. The best quality. A perfect fit between blades, ferrule and point. New Archery is constantly improving Thunderhead components so you can trust Thunderheads on price, quality and performance - every time! High Carbon Steel Trophy Tip is hardened for the most devastating durability available on the market. Stainless Steel Blades have the exclusive Diamize Edge for a visible super-sharpness you can see New Archery patented scooped out Slimline ferrule improves flight and penetration Patented lock Ring O-Ring Blade Retention System, perfect head alignment, and cushions blades on impact