Features: 1.Fittment:Diesel Compression Test Adapt Adapter uses with STAR Diesel Compression Tester TU-15. Compatible with GM: Duramax 6.6L Turbo Diesel (2005-present). Also works on a Duramax LML engine. 2.Material:Diesel Compression Tester Adapter is made of high quality steel and copper. Features high strength, anti-corrosion, anti-burst. Suitable for use in wet or dry environments. Reliable use, offer the quality, reliability, and durability you expect and save your charge. 3.New Design:M10-1.25 thread adapter with quick disconnect screws into the head of the engine in the glow plug hole. Manufactured to specific thread tolerance standards. .