Sorry I should have said heat tape. Available in different lengths. Package says 7 watts per foot seems like a lot to me. Today as a test I went into the outbuilding plugged in a long enough extention cord to reach the bedroom of the rv and plugged in the heater and turned it on high. Made sure the heat tape was on and the breaker didn't trip so I pulled the cord up though the access under the bed. Turned the heater back on and went back out to put things back in the building and when I turned the light on it tripped the breaker in the house going to the sub panel. The lights and outlets are on a different circuit, but 30 amp breaker in the house wasn't having it. So I will have to remeber not to flip the light on if I need in there, or unplug the heat tape for the time.