Specified range is most commonly found on Japanese manufactured radiators and can also be found on some late-model water-cooled American V-Twins. Unique design allows you to test the cooling system on a running engine to check for leaks or excessive pressure when system is hot. Unique radiator adapter will work with most motorcycle, ATV and UTV applications equipped with a 30 mm spout. Use with a common hand pump to pressurize a non-running system (pump not included). Remote, accurate, easy to read gauge makes readings and diagnosis easy. Tests radiator and radiator cap for leak and correct pressure release limit. Designed to work on radiator necks ranging from 15.75 mm to 20 mm. Pressurize motorcycle or ATV cooling system to check for leaks. Adapter also available separately..