Features:An essential component for building a high-performance, high-revving CRF motorRequired when using the BBR High Performance camshaft for the CRF150F/230FBuilt from the highest quality chrome-silicon wireFully shot-peened and preset for long lifeSpecifications:Product Name: SpringType: ValveMaterial: Chrome-SiliconUnits: PairRiding Style: Off-RoadAdditional:Brand: BBR MotorsportsPart Number: 411-HCF-1504Alternate Part Number: 0926-0209California ResidentsWARNING Cancer and Reproductive Harm. www.p65warnings.ca.gov