Never mind. Found it. - Where can I find a triangular waterstone holder

I'm looking for a waterstone holder/pond that is triangular and holds a stone on each side. Once you finish with one stone you rotate it to bring the next stone into place. Currently I'm using a pair of the Veritas ponds to hold 4 stones so they're always available but I'd like to reduce the footprint on my sharpening bench since I'll be using 3 stones now.

What reminded me of these was seeing one on a Peter Galbert video on sharpening. I can find one for oil stones but not for waterstones. I've seen them in the past but can't remember where.

Thanks.
Cliff