The Matco Tools TH209 Professional Circuit/Parasitic Drain Tester tests circuits up to 80 amps using the fuse contacts instead of connecting the amp meter to the circuit. Unit tests mini, maxi and ATO fuses and can be used on all domestic and foreign makes and models. The Fuse Value button allows the user to select a specific fuse ranging from 5A to 80A to get precise readings. The tester verifies if a fuse is blown, if there is a parasitic drain, or if there is no connection. This tool is not polarity-sensitive when contacting test leads to fuse contacts. Made in the USA.