The Ignite 4 is designed for maximum cutting surface with its main blades and bleeder blades all razor-sharp and replaceable and held in by NAP's secure X-lock system. Each blade is spin tested to ensure straightness and the package comes with practice blades so you can know exactly how they're going to shoot out of your bow before you get to the field! Four blades for a larger wound channel Grade 5 titanium ferrule X-Lock blade retention Crossbow rated 1 3/16" cutting diameter