You can do 2 4X5s in a 4X5 Beselar paper drum. I also have the Unicolor film drum and reels, but the gaskets are worn out and they (2 tanks) leak. I have not looked into making replacement gaskets, but I guess it is a possibility. I can only fit 2 4x5s in the Beselar and when I shoot 4x5 I may expose 20 to 30 negatives, so I use either trays or tanks with hangers.