Fits GLOCK Models: 26, 27, 33, 39 - GEN 3,4, & 5. For 2-pin only, does not fit 3-pin. One of the greatest things about GLOCK pistols is that available aftermarket parts are in abundance. Many of these parts have been strictly OEM, but MATCHPOINT USA aims to change this with their new precision machined, match-grade locking block for GLOCK Pistols. MATCHPOINT USA’s Locking Block for GLOCK pistols is machined to stricter tolerances than a metal injection molded (MIM) OEM part, ensuring a more predictable, and consistent lock-up. MATCHPOINT USA's Locking Block for GLOCK is machined from billet 17-4 stainless steel with a Rockwell Hardness rating of 44C, hard enough to last a lifetime of shooting round after round. Machining the part with these exact tolerances also maximizes the total amount of bearing surface possible with the barrel lug which helps aid in wear resistance in addition to providing a more secure lock-up. MATCHPOINT USA is the original designer and manufacturer of this fully CNC machined Locking Block. We also specified the proper material and hardness, tolerances, prototyping. This is why our quality and craftsmanship is second to none.