SLR-B56 Billet Lower ReceiverSpecifications:Machined in house from 7075 Billet AluminumWorks will all known AR15 upper receiversMil-Spec internal dimensions , Low ShelfVery tight fitting on upper receiversBlack Type 3 Mil-Spec Hard CoatThreaded Bolt catch. No roll pinsThreaded rear take down detent boreThis lower works with magazine restricted systems like the JT hellfigher Mod Kit.Weight: 9.0ozCompatible with PDW style stocksDue to unprecedented order volume , there is a 2-3 week lead time on processing serialized parts at this time.Cerakote will add additional time to shipping. If you would like the upper and lower done in two different colors, please leave a comment in your order.