3316250.712 Digital LED Black Thermostat For RV/Camper Conditioners The 3316250.712 wall thermostat can be used on all single zone cool only, heat pump and heat strip model air conditioner in RV, trailer or camper. Work with non-ducted or ducted rooftop A/C units. Compatible with 457915, 459516, 459530, 540315, 540316, 640310, 640310C, 640312, 640315, 640315C, 640316, 640316C, B57915, B59516, B59530, B79516, H540315, H540316.