Check the listing for details. 4 Inch Draft Blocker Backdraft Damper Duct Draft Stopper One-Way Airflow Ducting. Color: Sliver, Condition: New. Listed at 17.85 USD. Store New Arrivals Add to Favorite View Feedback Contact 4 Inch Draft Blocker Backdraft Damper Duct Draft Stopper One-Way Airflow Ducting Insert Backflow Preventer Inline Fan Vent Deflector 4 Inch Draft Blocker Backdraft Damper Duct Draft Stopper One-Way Airflow Ducting Insert Backflow Preventer Inline Fan Vent Deflector 【Material】The 4 inch backdraft damper is made of a Galvanized steel, the flap leaves are made of aluminum, while the Axis and spring are made of stainless steel.【Installation】The backdraft damper is installed by pushing it into the ventilation pipe as far as it will go. The position of the spring should be horizontal when the flap is installed horizontally so that it can be opened and closed optimally. This also applies to the vertical installation.【Function】This airflow regulating backdraft shutter fits over the TD lip and is designed to improve ventilation by preventing air from re-circulating when the fans are not in use.【Wide Application】 These backdraft dampers can be widely used in ACs, exhaust fans, extractors, range hoods, heating ducts, vents and other residential, commercial and industrial applications.【Note】Back draught valves can be inserted into ventilation ducts which are flexible or non flexible. Cannot be used with plastic ducts as the sizes are different. All dimensions are measured manually, please allow 1-3mm differences. Product Description About Kikerike Backdraft Damper The backdraft damper is made of a Galvanized steel, the flap leaves are made of aluminum, while the Axis and spring are made of stainless steel. Designed for use in AC, dryer vent, exhaust, extractor or range hoods, heating systems, fans, vents and other residential, commercial and industrial HVAC applications. Please consult and pay attention to product size before buying. Manual measurement, please allow slight errors on size. The colors may exist slight difference due to different screens. Specifications Color: silver Diameter: 3.9" / 10cm; 4.88" / 12.5cm; 5.87" / 15cm; 7.83" / 20cm; 10" / 25cm; 12" / 30cm Package includes: 1 x Balancing Barometric Damper Product Dimensions: 4.49 inches x 5.43 inches x 3.66 inches. Weight: 4.6 oz About Us Our vision is to be eBay’s most customer-centric store, where customers can find and discover anything they might want to buy online, and endeavors to offer its customers the lowest possible prices." "Our mission is to serve consumers online and focus on selection, price, and convenience." #Find it, Love it, Buy it Payment policy We currently accept payment via eBay managed payment only. Once payment is cleared, We will dispatch your shipment with 1-3 business days. Please refer to the "Shipping" tab for more information regarding shipping speed to your destination. Shipping policy 1. We offer FREE shipping on all orders! 2. We ship within three business days of payment, usually sooner. 3. We use a selection of shipping services such as UPS, FedEx, USPS etc. 4. We only ship to the lower 48 states, no APO/FPO addresses or PO Boxes allowed. 5. Local pickups and combined shipping options are not provided at this time. Returns We are committed to your happiness. That’s why we offer a 30-Day Return Policy on items that you are not completely satisfied with. You have the option for a refund or an exchange of the item.