The O.Z-9 Modular Build Kit (MBK) offers complete customization to build your O.Z-9 from the ground up. Start your custom build by choosing between a Black DLC or Titanium Gray colored O.Z-9 steel receiver. Using compatible ZEV components you get to pick and choose your ZEV slide ZEV barrel ZEV trigger ZEV O.Z-9 grip and ZEV O.Z-9 magwell to build the O.Z-9 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 O.Z-9 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. - In addition to an O.Z-9 Steel Receiver in either color each O.Z-9 MBK includes the following necessary components to complete your build: - ZEV O.Z-9 Slide Lock Lever and Spring - ZEV O.Z-9 Trigger Pin - ZEV O.Z-9 Ejector Housing Pin - ZEV Enhanced Extractor - Extended Slide Release Lever