The Electronic Specialties Starter Buddy, No. 165, speeds up the starting/cranking diagnostic procedure and finds high resistance in the circuit. This product performs a live cranking test on the vehicle to determine exactly which part of the electrical circuit has the issue. To find resistance issues, the tool makes three connections to the vehicle, then samples the live cranking voltage at each point. Starter Buddy pinpoints any excessive voltage drops and identifies which part of the circuit has the problem. One connection is made, one crank tells the story. Starter Buddy works on both 12V and 24V systems and includes a DVD with three 15-minute videos explaining, teaching and demonstrating the process. The 165 also includes an instruction manual, zippered carrying case and a one-year warranty. This tool is made in the U.S.A.