Mityvac 5530 Professional Compression Tester Kit Air hold quick connector allows user to attach air supply for performing valve seal replacement without removal of the cylinder head Full-coverage kit for automotive, industrial, marine, and small engines Includes heavy-duty 2 3/4" gauge with 10" whip hose-gauge, rubber boot and various sizes of hose and adapters Kit comes in a molded case for easy storage Adapters to fit engines as small as lawn mowers, chain saws and trimmers