This Zaffiri Precision aftermarket slide is machined from single billet 17-4 stainless steel. These slides are made with tight tolerances that allow an increase in accuracy and performance. Made and manufactured at Zaffiri Precision's facility. These are among the best aftermarket slides available. FeaturesMachined from billet 17-4 Stainless SteelOptic Cut - RMScSlide is pre-cut and pre-CerakotedBlack anodized optics cover plate included Note: This ZPS.2 slide NOT ported compatible. Optics Cut: Shield RMSc, Holosun 407k/507k, and Sig RomeoZero optic cuts are all the same footprint with NO rear lugs and slightly lowered front lugs. This makes the same footprint compatible with all 3 companies. Optic Cover Plate is included! The screws are all slightly different for optic mounting. Optic mounting position in front of the factory location of the rear iron sight. Screws are 6-32 thread. Blue Loctite recommended for proper sight retention.