I originally ordered a 4 rack but ended up getting another snake and had them switch it to a 5 a couple weeks after ordering. Mine is the 1754 one 15/32 quart tubs. I ordered it with belly heat and heat for the front sides since we tend to like temps around 73-74 in the house and its working great so far. I'm amazed how steady the temps are a definite improvement over the uth in my opinion. It took around 7-8 weeks and it was well worth the wait.