This is a 0 - 4A electronic load, with a max power dissipation of 50-100W depending on the heat sink you're using. The schematic is here: https://easyeda.com/jeanlemotan/jlm-electronic-load
The main use-case for this load is to characterize battery discharge curves.
UI and features: https://youtu.be/jkzM7wHbVtE
Schematic, PCB & Load Regulation: https://youtu.be/gcrGE7rbWiY