Engine Valve Spring Pressure Tester Trackside Analog 0-600LB Range On-Head Rocker Arm Mount ProformNeed to check spring pressure at the track? No problem with the PROFORM stud style valve spring compressor. This fully adjustable tool fits easily onto your rocker arm for pressure checks and will measure pressure up to 600 lbs. Oil filled gauge for smooth needle motion. Sold individually. Product Details: Engine Valve Spring Pressure Tester Trackside Analog Model 0 600LB Range On Head Rocker Arm Mount Style Made From High Quality Billet Aluminum Blue