Competition Cams 4929 Valve Spring Height Micrometer, 1.600"-2.200" Height Range Measures 1.600 inch-2.200 inch installed height Quickest, easiest, most accurate way to measure valve spring installed height Install just like a spring, then is expanded until it fully seats valve, locks and retainer. Simulated installation allows ultra precise readings Tool is read like a micrometer and is accurate to .001