The ZEV OZ9 Modular Build Kit (MBK) offers complete customization to build your OZ9 from the ground up. Using compatible ZEV components, you get to pick and choose your ZEV slide, ZEV barrel, ZEV OZ9 grip, and ZEV OZ9 magwell to build the OZ9 that best fits your needs, whether its duty, concealed carry, competition or a week-end range gun.Machined from a single block of 4140 alloy steel, the patented OZ9 internal steel receiver reduces the flex associated with polymer frames, has an integrated locking block and longer slide rails which provide more contact with the slide. This amounts to less felt recoil, less muzzle flip, faster follow up shots and improved accuracy. FeaturesCompatible with all compact and X-grip grip modulesExtended slide release leverIntegrated Picatinny Accessory Rail