OTC 5606 Compression Tester Kit Corrosion resistant nickel plated finish Adapters work on both flat and tapered seat plugs Extra long 25 inch flex hose gauge assembly with quick coupler, allows easy viewing out of cluttered engine compartment 2-1/2 inch gauge features chrome bezel and rugged protective outer boot Dual scale gauge reads 0-300 psi and 0-2100 kPa Professional quality gauge with zero adjust feature.