Armaspec Superlight .223/5.56mm Gun Builders Kit SS/Black. Containing everything you need except for the trigger group and grip this is the perfect option for both experienced and new builders. The stainless steel parts are designed to be durable smooth and efficient even after regular use ensuring your weapon functions perfectly every time. This kit includes the entire bolt catch assembly as well as everything you need for the magazine catch and release and the takedown/pivot pins. Specifications for Armaspec Superlight .223/5.56mm Gun Builders Kit: Manufacturer: Armaspec Caliber: 5.56x45mm NATO Gun Make: AR Platform Gun Model: AR-15 Gun Type: Rifle Country of Origin: USA Features of Armaspec .223/5.56 Superlight Gun Builders Kit Includes Armaspec Enhanced Lower Parts Compatible with most AR-15 lowers made in specialized factories Lifetime Warranty Package Contents: Armaspec .223/5.56 Superlight Gun Builders Kit Armaspec ARM251-BLK: Superlight .223/5.56mm Gun Builders Kit SS/Black