Part #36 in the list. There's two listings, one is for the manual (knob) and one is for the automatic. It'd be more helpful if it wasn't facing the wrong way... There's actually a third kind, I think (not listed here). Contact Nalley before ordering to confirm, but I'm pretty sure the $200+ one is the digital one. Make sure to ask if it's just the fan speed one, or fan + temperature if your TB EXT has that equipped.