Grey Ghost Precision AR-15 Receiver Set, Semi-automatic, Lower/Upper Set, 556NATO, Black, No Handguard, Billet, Hard Coat Anodized GGP-S-LIGHT-RCVR-BS The MKII version of the GGP-P Series brings a new level of customizability never before seen in their rifle receivers. Not only can you build your own version of the Heavy or Light rifle, but you can use your favorite aftermarket parts to complete the weapon of your dreams. The lower receiver includes their ambidextrous bolt release as a standard feature. Start your build off right.