Well I assembled the parts for this one. The voltmeter is 1ma movement panel meter that I made into an expanded scale voltmeter. Ammeter is a 0-50mv Simpson meter being fed by a 100 amp 50mv shunt. Put it with the 100 amp carbon pile and you have a brute force battery tester. Great for Lipo testing and discharging to the storage voltage if the battery did not get used and is still at full charge. I use these for my shop battery powered drills and model airplanes of course.