When I built my Voron Zero I was concerned at the ease at which someone could touch the mains voltage terminals on the PSU if the skirts (not supplied in the PiF kits) were missing.
Additionally, the finger guard provided didn't feel secure enough to stay in place and could be removed without a tool. UK regs state that no one should be able to touch voltages likely to cause injury or death without a tool.
This is an upgraded cover that clips in one end and uses an M3 bolt on the other. It fully encloses the terminals and has a recessed reminder on the top.
The author hasn't provided the model origin yet.