Maxxair 00-04000k MaxxFan RV 12V Roof Vent – White – Manual Opening – Ceiling ControlsThis roof vent’s highly adjustable 12-volt fan and built-in thermostat give you maximum control over ventilating your motorhome or enclosed trailer. Rounded, low-profile, white translucent plastic dome operates manually. This roof vent gives you a high level of control over ventilating your RV or enclosed trailer. You can set the fan’s direction to exhaust hot, stale air or pull in fresh, cool, outside air. You can also adjust the fan’s speed to control the volume of air movement. Or you can set the thermostat, and the fan will automatically vary its speed to keep your trailer comfortable, freeing you from the trouble of constantly adjusting the fan yourself. With two lifting arms, the MaxxFan roof vent provides sturdy support for the lid. It’s strong enough to handle high winds and to stay fully open while you’re driving. Unlike typical vents that use just one arm,