Quote Originally Posted by Stefan-A View Post
Doesn't make much sense, though. It's much too low to be used as an aquarium.

I think the lids are from a universal mould, and the bottoms vary in height, so the same lid that would be on a low keeper could also be used on a taller one.

It's cheaper to manufacture anything if the parts interchange.

It would make sense to have a knock out where the hole is, so the end user can decide if they want the hole or not.