Great for motor blowers. Original fuse is replaced in-line during testing, thereby maintaining circuit protection. Great tool for electrical troubleshooting at the fuse box. Can be used on all circuits up to 30 Amps. Test range: 0 - 30 Amps - 48V DC - .1A resolution New Fuse Buddy is capable of measuring up to 30 Amps. Blowing Fuses? Plug in the Fuse Buddy and read the circuit amperage draw. Clever amp meter is very handy when working with circuit amperage issues. Very easy connection into ATC Blade fuse socket, the end of the tester is shaped just like a fuse. One year warranty.