Gorilla Glock 19 slides are machined from solid billet 416 Stainless Steel with a DLC (Diamond Like Carbon) coating that it extremely tough and durable. All slides come with a RMR optic cut, with an option to add a cover plate. These are stripped slides with no internal components. We offer Channel Liners on our website at: https://www.gorillaammo.com/product/zev-technologies-channel-liner-for-glock-slides-red/ **If putting the Gen3/4 slide on a Gen 4 frame a Slide Adapter Plate and Gen 3 recoil spring are required. Slide Adapter Plates can be purchased on our website at: https://www.gorillaammo.com/product/strike-industries-slide-adapter-plate-g-sap-for-glock-gen3-to-gen4/