I've got 6 of these overflows made by me. I had them on some 40 breeders. Come with a U pipe for each one. Asking 15.00 each obo. If you want them all I can work out a sweet deal.
they all have durso pipes on them so they are pretty quiet. I had 6 tanks hooked up to a common sump system and it had an iwaki 40 xlrt as the return pump. So I put probably 160 gallons per hour through one overflow. Each one has a 3/4 drain on it and a 1" U tube.