The Norsso Reptile KP Slide & Barrel Set includes one Reptile KP Slide and one Norsso 3.7" 9mm Bull Barrel. Both parts are machined from 17-4 PH Stainless Steel. FeaturesMilled with the RMSc Shield/Holosun 507K/EPS Carry footprintAggressive scale cut serrations overlapping Norsso signature 3D dynamic machined windowsSawtooth corner features surrounding a concave, knurl-inspired portErgonomic forward and top serrations for easier press checks and slide rackingLarger barrel bore only compatible with Norsso N365XL Bull BarrelsMultifaceted contoured front and rear corners