Kelford Cams racing valve spring kit for the VW Audi EA888.3 MQB Platform. Models include: Audi TT, Audi A3, Volkswagen Golf. Premium quality spring steel wound in USA by PAC. Made with advanced heat treatment processing and surface finishing techniques (nano peening) to extend fatigue life. Valve springs designed with a high spring frequency for superior spring surge control at high RPM and boast a +30% higher seat pressure than the OEM spring. This beehive valve spring kit is specifically designed for high boost and high RPM applications. IN: 36.2mm installed height. 100lbs on seat. 210lbs at 11.5mm open. 12mm max lift. EX: 35.1mm installed height. 110lbs on seat. 220lbs at 11mm open. 11mm max lift. Install supplied spring seat on both intake and exhaust.