Anyone with average- to small hands now can easily perform magazine changes without shifting their firing grip on the weapon. The VT GMR-004 is easy to install, and made of the same tough polymer as the Glock™ factory part. The extended catch is just perfect…not too short, not too long, i.e. the magazine will not accidentally release if pistol is laid on a hard surface. Perfect with use of back strap mounted lasers. For Gen 4 pistols only. Not for use with Gen 1, 2, & 3 pistols. Fits Glock™ models G20, 21, 29, 30 and 41.