The Marksman V4 Slide for Glock G19 Gen3's is machined from hardened 17-4 stainless steel to ensure long lasting performance. Precisely machined RMR pattern with 2 alignment recoil bosses. Features compatibility with Trijicon RMR, SRO or Holosun 507 red-dot optics. Front & rear serrations for enhanced slide manipulation. Compatible with 3rd Gen 9mm slide internals (not included). Compatible with Glock G19 Gen 3 & P80 PF940C frames. QPQ Nitride finish. Certified Gunsmith assembly recommended. Mfg: Alpha Shooting Sports