This is a 10 KV high pot tester. The input voltage is 120v ac. The output is a DC output that can be varied from 0 to 10KV via a rheostat. The capacitors, HV diodes and transformers are all commercial grade. It has a large red pilot light to indicate when it is ON.
It is housed in a compact carrying case. The unit weights about 15-20 pounds.
I used it when I was building some high voltage power supplies for amplifiers. I used it to check Vacuum variable capacitors, HV diodes and leakage on oil filled capacitors.