Feature:1. DOUBLE VENTILATION FANS: Equipped with 2 fans for easy switch between inlet and exhaust, providing clean air circulation and water resistant sealing for RV, camping vehicle, motorhome, etc.2. HIGH DURABILITY: Made of engineering grade ABS material with excellent weather resistance, UV resistant, anti aging, and impact resistance, and non yellowing even after long time exposure to sun.3. STAINLESS STEEL SUPPORT ROD: Features a stainless steel support rod with adjustable angle (031.5) for easy installation and support. Comes with a seal strip to ensure water resistant sealing.4. EFFECTIVE DEBRIS BLOCKING: 340x340mm opening size with stainless steel net to prevent flying objects from entering the cabin. Suitable for bathrooms, kitchens, warehouses, lounges, etc.5. VENTILATION SOLUTION: Ideal for providing clean air circulation and repairing leaking roofs for marine boats, yachts, etc. Easy to install and use for indoor outdoor air exchange.Specification:Item Type: RV Roof Vent FanMaterial: ABS, Stainless SteelWorking Voltage: DC12VInstallation Opening Size: Approx. 340x340mm / 13.39x13.39inFan Dimensions: Approx. 420x420x134mm / 16.54x16.54x5.28inSuitable Installation Thickness: Approx. 20-55mm / 0.79-2.17inFeatures: Dual fan design with one key switch for intake or exhaust, equipped with stainless steel screen and support rods, support rods adjustable from 0-31.5 via knob, white top cover to block sunlight and ensure water resistant seal with sealing stripApplication: Suitable for RVs, Camping Vehicle, Motorhomes, Trailers, CaravansInstallation Steps: 1. Identify installation location and mark it2. Use hole saw to make a 340x340mm hole3. Insert fan into the hole and connect circuit, red wire connects to power positive terminal, black wire connects to power negative terminal4. Install fixing clamp and secure with screws for completionNote: If you have a leaking or localized hole in the roof of your compartment, this vent can be used as a patch piece to install in the damaged location, providing ventilation inside the compartment and repairing the hole at the same time..Package List:1 x Roof Ventilation Fan1 x Support Rod Knob1 x Knob Fixing ScrewNote:1. Installation requires drilling and wiring, we strongly recommend having a professional engineer install it to ensure your best shopping experience. 2. The direction of the exhaust fan opening must be opposite to the direction of the hood, if not installed according to the method, severe cases may cause the cover of the exhaust fan to flip open during high speed driving.