yeah 100 for the basic model, to me flex watt is easier to do for a single tub(my GTP is on a single tub) and the flex watt stays a constant 87 hot side and 82 cold side for the tub, and my bp are in a rack, JCP in a cage, and flex watt is cheaper than a UTH in the long run, a 2ft section hooked up is around $10 from RBI and will last you for all the tubs a bp will need from baby till adult, where are for bigger tubs you will need to buy bigger UTH for each size tub.

Tom