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.Features :ZEV O.Z-9 Slide Lock Lever and SpringZEV O.Z-9 Trigger PinZEV O.Z-9 Ejector Housing PinZEV Enhanced ExtractorExtended Slide Release Lever