Double Star uses only the best parts to make their lower parts kits. The fire control group is made from Mil-Spec heat treated 8620 steel and finished on all touch points for a smooth, crisp trigger pull with minimal creep or drag. This AR-15 lower parts kit uses high quality American made parts to ensure performance in your AR-15. Features: Includes an additional takedown detent and spring Coiled steel spring pins Crisp trigger pull with minimal creep or drag