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. The P4B also features a revolutionary Nano Composite Parts Kit. This kit includes the hammer, trigger, disconnector, takedown pins, safety selector, magazine release and detents all made from nano composite material that is just as strong as metal components but at only 1/2 the weight. - CALIBER .223 REM/5.56MM NATO - MAGAZINE (1) magazine with 30rd capacity - BARREL 7.5" 1:7 Twist Nitride M4 5.56 x 45mm Barrel - RECEIVERS Patented Omni Hybrid with Front & Rear Metal Inserts - HANDGUARD 7" Keymod Free Float Rail - BRACE Trinity Force Breach Brace"/\