These racks are awesome! I love them and will be purchasing more racks from RBI in the near future. A few things about the racks though. They don't take rough usage well. I don't think any racks do but my 3 tub CB70 rack for my adult females is having some issues. The heat tape has stopped working but I think that is my fault. The sweaterbox racks come with little pieces of wood over the heat tape that act as risers to keep the tubs from sliding back and forth over the heat tape. This protects the heat tape and the probe from being pulled up. The CB70 rack does not come with this and the heat tape on the second level has come up and I had an issue with the probe being pulled off. I did have a little mouse family make a home on the bottom level though when I lived in my apartment (feeders got loose from their tank and found their way to my racks. The heat tape attracted them to the rack and they made a little nest near the heat tape behind the tub out of paper towel and small pieces of cardboard. Ugh! I am going to replace this rack.
The sweater box racks are awesome but I do have one issue with these. I have two stacked on top of each other and one tub is extremely tough to pull out and push back in. I'm not sure why this happened but maybe its the rack's frame warping. I'm not sure, but again, it was probably my fault.