excellent quality tool i work at a dealership and this works fine i trust its results great must have alot smaller pump as my original one that i had five stars maybe i got a bad one but even though it has the stant so so you get what you pay for five stars works great piston was a bit sticky five stars poorly constructed terrible qc even the instructions admit the tool wont seal well make exactly what i needed cooling system tester and adapter set a good tester 40 years and mine still works like new