OMNI HYBRID MAXX P4B features a fully-patented metal reinforced polymer upper receiver along with a fully-patented metal reinforced polymer lower receiver. The Omni Hybrid lower features a patented hammer and trigger pin retainment system, preventing movement from the hammer and trigger pin during firing. The Omni Hybrid also features our patented over-molded metal inserts, which reinforce the buffer tube housing and rear takedown pin as well as reinforce the front take down pins. This allows for metal-on-metal contact with both the buffer tube as well as the rear takedown pin thus increasing strength and durability from recoil and consistent firing.