Colku GCA26f Constant speed 100-120v RV rooftop air conditioner with 2500W/8500BTU cooling capacity, GMCC inverter compressor, is one of coolest rv roof air conditioner we have ever built. It can change speed stepless and less vibration, working with Colku specially developed compressor control box, can reduce compressor vibration and annoying resonancen. It has modern looks and superior performance, can cool down your motorhome, caravan or campervan with about 200~240 square feet. Colku Rv roof ac units can truly achieve cool down your vehicles faster, more quietly and more efficiently than any other rv air conditioner around. If you need, you can also use the warming function of our ac units in winter.