--- product_id: 457438119 title: "WeCooper 100mm - 4 inch Connector with Backdraught Shutter, Non-Return Damper Flap to Connect Duct Pipe or Flexible Hose Pipe" brand: "wecooper" price: "£19.80" currency: GBP in_stock: true reviews_count: 13 category: "We Cooper" url: https://www.desertcart.co.uk/products/457438119-wecooper-100mm-4-inch-connector-with-backdraught-shutter-non-return store_origin: GB region: United Kingdom --- # 100mm (4 inch) precision fit One-way airflow with backdraught shutter Galvanized steel & aluminum durability WeCooper 100mm - 4 inch Connector with Backdraught Shutter, Non-Return Damper Flap to Connect Duct Pipe or Flexible Hose Pipe **Brand:** wecooper **Price:** £19.80 **Availability:** ✅ In Stock ## Summary > 🚀 Elevate your airflow with precision and power — don’t let backdrafts hold you back! ## Quick Answers - **What is this?** WeCooper 100mm - 4 inch Connector with Backdraught Shutter, Non-Return Damper Flap to Connect Duct Pipe or Flexible Hose Pipe by wecooper - **How much does it cost?** £19.80 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.co.uk](https://www.desertcart.co.uk/products/457438119-wecooper-100mm-4-inch-connector-with-backdraught-shutter-non-return) ## Best For - wecooper enthusiasts ## Why This Product - Trusted wecooper brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Noise-Reducing Seal:** Inner rubber and outer foam seals ensure tightness and minimize operational noise for a quieter environment. - • **Precision 100mm Fit:** Seamlessly connects to standard 4-inch ducts and flexible hoses for hassle-free installation. - • **Robust Build Quality:** Crafted from galvanized steel casing and aluminum blades for long-lasting corrosion resistance and strength. - • **Versatile Application:** Ideal for tumble dryers, extractor fans, air conditioners, hydroponics, and more—upgrade your airflow game. - • **Smart Backdraught Shutter:** Automatically blocks reverse airflow, keeping your ventilation system efficient and energy-saving. ## Overview The WeCooper 100mm (4 inch) Connector with Backdraught Shutter is a high-quality non-return damper designed to fit standard duct pipes and flexible hoses. Featuring a galvanized steel casing, aluminum blades, and stainless steel shaft with spring, it ensures durability and reliable one-way airflow control. Its noise-reducing seals and strong spring mechanism make it perfect for ventilation systems in homes and professional setups, preventing cold air backflow and enhancing system efficiency. ## Description Wecooper 100Mm 4 Inch Connector With Backdraught Shutter, Non Damper Flap To Connect Duct Pipe Or Flexible Hose Pipe Review: Dimensions as described, performs very well - Very well made, all dimensions correct, perform perfectly ( although I'm using it with AEG kitchen hood which in full trhotle pumps 700 cubic meters of air per hour, on lowest settings probably about 150 ) with it works perfectly.Spring holding back draft flap is quite strong, than if someone going to use it with not as such powerful units (like washing air dryers etc) might not be suitable, but it's just my guess, can't tell for sure, you need to baisycly try it. Review: Quality damper/NRV - Really like the quality of the WeCooper range of dampers and NRV. I use these when I can and have 3 In use personally. Unfortunately, I wanted a 125mm dia, and couldn't locate this size in the WeCooper range. ## Features - Pipe cover flap, butterfly valve. Especially suitable for inserting into 100mm round pipe or 102mm flexible hose. Perfect for use in Tumble Dryer, bathrooms, garages, air conditioners, extractor fan, extractor hoods, Hydroponics, In-Line Extract Fans, and ventilation systems - The flap valve opens and closes automatically, allowing only one-directional airflow, blocking cold air into your extract fan or ducting. The damper blades open only in the outflowing air direction when the shutter is installed. The shaft axis need be positioned vertically when the backflow flap best installed in a horizontal position and inserted fully into the pipe. This also applies to vertical installation - The casing of the flap is made of galvanized steel sheet. The valve blades are made of aluminium. The shaft and spring are made of stainless steel - The inner rubber seal is used for better tightness and for noise reduction. The outer foam sealing strip provides good tightening and fixing of the backflow flap inside the duct. The flap valve can be inserted into a non-flexible metal or plastic duct directly, but for flexible duct you must use steel duct clamps to secure the backdraft damper - You can't go wrong in purchasing this ducting connector with inline backdraught shutter or gravity damper flap. Please get in touch with us directly with any questions. We will reply within 24 hours ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B09H5DBB7W | | Batteries Required? | No | | Batteries included? | No | | Best Sellers Rank | 6,448 in DIY & Tools ( See Top 100 in DIY & Tools ) 11 in Ducting | | Certification | EN 10204, EN 10206 | | Colour | Silver | | Customer Reviews | 4.1 4.1 out of 5 stars (969) | | Date First Available | 25 Dec. 2021 | | Item Weight | 150 g | | Item model number | 208672c9-b911-4d76-a6cc-85e645db2f22 | | Manufacturer | WeCooper | | Material | short | | Package Dimensions | 28.5 x 21.8 x 6.2 cm; 150 g | | Size | 4 inch | ## Product Details - **Brand:** WeCooper - **Exterior finish:** Stainless Steel - **Inlet connection size:** 4 Inches - **Inlet connection type:** Female Iron Pipe - **Manufacturer:** WeCooper - **Material:** short - **Number of ports:** 2 - **Outlet connection size:** 4 Inches - **Outlet connection type:** Flare - **Specification met:** EN 10204, EN 10206 ## Images ![WeCooper 100mm - 4 inch Connector with Backdraught Shutter, Non-Return Damper Flap to Connect Duct Pipe or Flexible Hose Pipe - Image 1](https://m.media-amazon.com/images/I/51SrnFkhhoL.jpg) ## Available Options This product comes in different **Size** options. ## Questions & Answers **Q: Does this damper fit completely inside the duct or is it a coupler for attach duct on both ends ?** A: I would say that it’s a coupler for ducting. I placed mine inside the wall and attached ducting either end. **Q: Is it better to place this right before the fan or right after?** A: I don’t know if it will make any difference. I have positioned mine after the fan, only because of space restrictions. **Q: hello can this be fitted to a kitchen extractor fan ?** A: In my opinion it wouldn't fit a window extractor. However, if 100mm trunking is used on the fan exit I would think it will fit the internal trunking. **Q: We have an in-line fan with 100mm flexible ducts on both sides. Where is the best place to put this flap?** A: Without actually seeing the placement and type of ducting, place the flap as close as practical to the fan unit exit. I actually fitted mine to the exit side body of the fan. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Dimensions as described, performs very well *by G***G on 16 October 2025* Very well made, all dimensions correct, perform perfectly ( although I'm using it with AEG kitchen hood which in full trhotle pumps 700 cubic meters of air per hour, on lowest settings probably about 150 ) with it works perfectly.Spring holding back draft flap is quite strong, than if someone going to use it with not as such powerful units (like washing air dryers etc) might not be suitable, but it's just my guess, can't tell for sure, you need to baisycly try it. ### ⭐⭐⭐⭐⭐ Quality damper/NRV *by S***H on 8 January 2026* Really like the quality of the WeCooper range of dampers and NRV. I use these when I can and have 3 In use personally. Unfortunately, I wanted a 125mm dia, and couldn't locate this size in the WeCooper range. ### ⭐⭐⭐⭐ Good item let down by springs that are too strong *by L***. on 18 September 2025* Fits perfectly and mostly does its job but as others have said the springs are too strong so I recommend removing one of them being metal no doubt its durable and haven't really noticed any noise the seal is good and its as simple as pushing it in ## Frequently Bought Together - WeCooper 100mm - 4 inch Connector with Backdraught Shutter, Non-Return Damper Flap to Connect Duct Pipe or Flexible Hose Pipe - TUPARKA 4 Pack Large Size Metal Hose Clips 91-114 mm Adjustable Ducting Clamps for Securing Hoses and Pipes Tube - Manrose, MF100T, black --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.co.uk/products/457438119-wecooper-100mm-4-inch-connector-with-backdraught-shutter-non-return](https://www.desertcart.co.uk/products/457438119-wecooper-100mm-4-inch-connector-with-backdraught-shutter-non-return) --- *Product available on Desertcart United Kingdom* *Store origin: GB* *Last updated: 2026-05-26*