YuanChi LED display switching power supply (model YC-400W3-5V). Supports 100-240VAC in, outputs 5V @ 80A/400W. Units were used in a large LED display screen to power LED receiving chips and LED panels. Full product details here: https://www.myledcard.com/yuanchi-yc400w5v-led-display-power-supply-p-978.html
(I'm not associated with that website, it just was the one place I could find a full set of product details)