This AR15 lower parts kit uses high quality American made parts to ensure performance in your AR15.Why Choose DoubleStar Lower Parts Kits instead of the "Other Guys?"DoubleStar 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. Lesser lower kits use metal injected molded or improper steel to cut costs. The lesser part will wear at an extremely high rate and need replacing sooner. They also make for a terrible, heavy, gritty trigger pull. DoubleStar parts are made to last for the lifetime of the weapon. Another advantage to our kit is the use of coiled steel spring pins instead of the standard split roll pins. Not only are they easier to install, but they also flex outward once installed giving them less chance to work their way out. As a bonus, DoubleStar includes an additional takedown detent and spring in case one flies away during installation never to be seen again. All parts are American Made, by real Americans. The real question is why would you choose anything else?