Rugged Mountain 11RL battery box manufacture

I was thinking box, not tray. Disregard.
But, 2nd thought, you might find a Rubbermaid type box at WalMart.
Does everybody's tray have holes in the corners? That makes no sense to me.
Can someone theorize about that??

While a phone call yield an answer,
at 2:09 this video shows tag but I cant quite make out
https://youtu.be/MGhOrvaG4Q0?t=130

Maybe Noco? Walmart, etc.

Looks like the Cirrus 820 uses one that's very similar.