Engine Cylinder Compression auto Tester Kit gauge M8 M10 M12 M14 Gas motor Completed kit comes with adapters For most applications Check the condition of your piston ring & valve seats 3" gauge features dual color scale. 0-300 PSI 0-20 kPa 4 Spark plug thread adapter: M8 x 1.5 M10 x 1.0 M12 x 1.25 M14 x 1.25 Quickly and accurately check compression on petrol engine 400mm flexible extension 2 Pc rubber cones ends For quick check (No need to thread into head) Blow mold case included