This is a fully ambidextroux model of our signature billet design with our new billet multi-caliber lower receiever. This receiver accepts calibers such as 5.56, .223, .300BLK, 6.8SPC, .22LR, 6.5 Grendel, and many more! 3D solid models available for Solidworks and most all 3D CAD Design softwares, other files types offered are step, and parasolid! This exclusive lower receiver offers a built in oversized trigger guard, upper receiver tensioning hole set screw hole, and also fits the PDQ ambidexrous bolt release to create a fully ambidexrous compatible receiver. Also will accept all mil spec compenents!