The Radian Compressor Quick Tune Guide Rod Kit has a screwless design. The dovetail interface is captured by the spring, creating a simple and secure lock-up. Flutes along the guide rod allow the spring to move with less friction for smoother cycling. The heat treated guide rod has a slick, durable, and corrosion-resistant Nitride finish. Includes:1 - Hardened 17-4 SS Guide Rod3 - Flat wire Springs in 13lb, 15lb, and 18 lb weights1 - SS Washer for Gen31 - SS Captive bushing for Gen4 & Gen5 compatibility1 - Spring compression tool 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.