The JE Machine Magazine Vice Block slides into the magazine well of your pistol to hold it steady for cleaning, assembly or repair. To ensure a snug fit in your pistol, the ridge on the back of the stem may need to be filed down. FeaturesEffective cleaning, assembly and repairSolid and heavy dutyFits all 9mm and .40 caliber Glock pistols DISCLAIMER: 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.