For Screamin” Eagle heads. Installed pressure 217lbs@1.789″; open pressure & height 415lbs@1.215″; coil bind@1.125″. Direct replacement; installs without machining or rocker box clearancing. High tensile chrome silicone wire with a shot-peened heat treatment and a super NexTexr finish. Kits include springs; lower collars; titanium upper collars; shims; keys and Vitonr seals.