The has been years in the making! XTech has mastered mag well compatibility and USPSA limited class gauges! The two piece housing design allows this extension to have a patented leading edge on the inner housing to goes into the magazine tube. This guarantees flawless feeding by eliminating the catch point at the transition from the extension to the magazine tube! There is not other magazine extension on the market that can say this! FeaturesLeading Edge Technology5 points of engagementExtended 17-7 Stainless Steel SpringProprietary Baseplate material for unmatched durabilityDISCLAIMER: This product is not manufactured, authorized, endorsed, or warranted by GLOCK. GLOCK does not warrant or represent that this product is compatible with GLOCK pistols.