The 20/21 Stabilizer Kit is the first affordable high quality kit for 10mm/45 ACP Large frame Glocks. Fits Glocks 20, 21, 29, 40, 41 (All Generations) IncludesStabilizer FrameFG20 Angled Forward Grip FeaturesReady for use out of the boxSimple installationUses the Gun's built in sights, no need to calibrate sightsCompatible with compensatorsCompatible with Red Dot opticsNo pistol disassembly or permanent modifications requiredLightweight and compactIncreases accuracyFully functional with folded stock