Zenith Firearms stands as a premier expert in the field of roller-delayed firearms, setting the standard for precision engineering and innovative design. With a rich heritage of craftsmanship and a commitment to excellence, Zenith Firearms is proud to introduce the ZF-56. The ZF-56 is a semi-auto firearm with a roller-delayed blowback operating system. The ZF-56 is chambered in 5.56 and comes with a full length Picatinny rail, & a cold hammer-forged barrel. The American Made ZF-56 also features a last round bolt hold open system.