This is the 3D model for the lower-lower part of Ghost Gunner's Zero Percent Receiver. This part can be printed on a 3D-printer and then mated to a metal upper-lower. A metal version of the lower-lower can be purchased from Ghost Gunner.
Blueprints for this model can be found here.
The metal lower-lower can be purchased as part of the Ghost Gunner Zero Percent Lower Build Kit at https://ghostgunner.net/product/zero-build-kit/.
Learn more about the Ghost Gunner Zero Percent Receiver at zero.ghostgunner.net.