Checks oil pressure in automatic transmissions and gasoline engines. 6 ft. of nitril (oil proof) hose to make testing easier, plus standard and metric fittings. The 2-1/2" gauge has a dual scale dial with ranges 0-300 PSI and 0-21 bar. Instructions and specifications included. All packed neatly in a plastic box This tester set is used to check oil pressure in automatic transmissions and gasoline engines. Also test most domestic and imported cars and light trucks more accurate than dashboard oil pressure gauges. It's especially helpful on cars with dash indicator lights only. This is an easy to use tester!