The Ultimate Spring Kit for your 19 is compatible with all variations of the Glock 19 from 1-6. This specific G19 Ultimate kit includes the adapter bushing for Gen 4, 5, and V Glock pistols and their aftermarket variants. Get the most out of your compensated or suppressed Glock 19 Gen 4,5, and V and copies (also compatible with Glock Gen 1-6 pistols), with this recoil spring tuning kit from True Precision. Built from high-strength chrome-silicon, these springs offer consistent, long-lasting performance in excess of 20,000 compressions each. This kit includes multiple spring weights to help you fine-tune your setup for reliable cycling and reduced recoil. Especially helpful with varying slide weights, ammo choices, and muzzle devices.