TOMEI Valve Springs In terms of transferring the exact movement of the camshaft, the highest quality valve spring is required to the high RPM , high powered tuned engines. Tomei's products with the most careful choice of the material, coating and the other technologies. Then Tomei repeated severe tests to Tomei's pre-production in order to give the best quality that is performed in any situations. Features Reliability in high RPM , and improvement in an initial response High durability against metal fatigue High durability against the shocks from jump and bounce High durability against surging High sag resistance