As said above it blasts harder than other testers.
Take a look at the schematic for the Beltron. There's really not much to it. Basically a power supply with some meters, switches and resistors.
http://www.fidnet.com/~seanbart/Belt..._Schematic.jpg
On the other hand, the CR_70 has transistors and op-amps to regulate and limit the voltage and current.
https://drive.google.com/open?id=1h6...i70iomevDZBg1m