No marking I think it's proprietary and custom made, but of course it had to be made by some sort of UL standard.Is there a listing mark?
It is often difficult to determine what standard a product has been listed to, ever where it is listed. If it was listed by UL, there should be an "E" number near the listing mark, and with some deep digging on the UL site you can determine the product standard it was listed too. Not as easy to do with products listed by other listing agencies.