The Radian Weapons Systems COMPRESSOR Quick-Tune Guide Rod for Glock utilizes a screwless design that creates a simple and secure lock-up. Most adjustable guide rods use screws that can loosen over time, and thread locker forces you to commit to one spring weight. But the COMPRESSOR comes with 3 flat wire springs in 13-lb., 15-lb., and 18-lb. weights, giving you plenty of versatility. Flutes along the guide rod allow the spring to move with less friction for smoother cycling. Heat-treated guide rod has a slick and corrosion-resistant guide rod finish. Works with G19 Gen1-5, G19X, G45, G47, and G49. Includes 17-4 stainless guide rod, 3 flat wire springs, stainless steel washer for Gen3, and captive bushing for Gen4 and Gen5 compatibility. Screwless design creates a simple and secure lock-up Works with G19 Gen1-5, G19X, G45, G47, and G49 Flutes along the guide rod for less friction Heat-treated 17-4 stainless steel guide rod Includes 3 flat wire springs (13-lb., 15-lb., and 18-lb.)