Mityvac MV5530 is a comprehensive kit that includes everything required to perform dry or wet compression tests on gasoline / petrol engines. Compression testing is commonly used to detect problems with rings, cylinder heads, sticking valves, failed head gaskets and more. The kit includes adapters for use on automotive, powersports, marine and small engines, plus an air-hold adapter for performing valve spring or seal repairs without removing cylinder head. Maximum pressure 300 PSI. This kit is NOT designed for use on diesel engines.