Vitally important but often overlooked most mass produced springs and detents on the market are a compromise of cost vs performance. Material choice will often have descriptors like easily machinable and cost effective. The Fortis Enhanced Detent & Spring Kit cuts no corners. Fortis uses only high grade Stainless Steel (17-4 detents & 17-7 springs) so there's no compromises. The benefits of corrosion resistance properties and toughness of 17-4 & 17-7 Stainless steel will enhance your firearms reliability in the harshest environments. FeaturesDetent Material 17-4 Stainless Steel (H900 Heat Treated)Spring Material 17-7 Stainless Steel Contents2x Takedown/Pivot Detent2x Takedown/Pivot Spring1x Safety Selector Detent1x Safety Selector Spring1x Buffer Retainer1x Buffer Retainer Spring1x Bolt Catch Plunger1x Bolt Catch Spring1x Magazine Catch Spring