The Matco Tools AC56000 Combustion Leak Tester provides a fast, economical and accurate method to test for combustion gas leaks in head gaskets, cylinder heads and engine blocks. With a dual chamber design, which they feel will offer more accurate results, according to the company, by eliminating the false positive readings of some single chamber units. Additional features include compatibility with both gasoline and diesel engines, as well as a rugged, foam-lined storage case. Test fluid can be used for both gasoline and diesel engines. The unit features 16 oz combustion leak fluid.