Description of the Product Function. The Manual Control of the Roof Ventilation Exchanges the Air in Your Motorhome or Caravan Within Minutes. It Removes Cooking Smoke and Unpleasant Aromas from the Bathroom and Lets You Breathe Fresh Outside Air. Breathe in Natural, Fresh Outside Air to Make Your Living Space More Comfortable. Equipped with Stainless Steel Insect Protection. Motor Made of Pure Copper Core, Reliable and Highly Efficient. Fan with 10 Blades, More Stable and Quieter. Waterproof and Soundproof, Difficult to Age. Item Sub-type: Fan for Roof Ventilation. Vehicle Type: Motorhome & Caravan. Hole Size: 280 280mm. Air Flow Rate: 10-15cbm / Min. 1 Roof Ventilation Fan with Led. Installation Instructions Are Not Included. Professional Installation Is Highly Recommended. It Is Recommended to Use a Neutral Structural Glue for Installation to Avoid the Bad Combination of Acidic and Alkaline Glue Which Can Lead to Bad Chemical Reactions like Corrosion and Glue Cracks. Manual measured, please allow 2-4mm error.