---
product_id: 504446575
title: "Repa Market 4\" Inch / 100 mm Duct Backdraft Blockers - Pipe Connector with Backdraught Shutter - Backflow Preventer - Dryer Vent Adapter - Inline Air Extractor - Pipe Line Coupler with Valve"
brand: "repa market"
price: "€ 26.69"
currency: EUR
in_stock: true
reviews_count: 13
category: "Repa Market"
url: https://www.desertcart.nl/products/504446575-repa-market-4-inch-100-mm-duct-backdraft-blockers-pipe
store_origin: NL
region: Netherlands
---

# Advanced backflow damper 3.89 inch insertion diameter DIY easy installation Repa Market 4" Inch / 100 mm Duct Backdraft Blockers - Pipe Connector with Backdraught Shutter - Backflow Preventer - Dryer Vent Adapter - Inline Air Extractor - Pipe Line Coupler with Valve

**Brand:** repa market
**Price:** € 26.69
**Availability:** ✅ In Stock

## Summary

> 💨 Stop the draft, keep the comfort — ventilation perfected.

## Quick Answers

- **What is this?** Repa Market 4" Inch / 100 mm Duct Backdraft Blockers - Pipe Connector with Backdraught Shutter - Backflow Preventer - Dryer Vent Adapter - Inline Air Extractor - Pipe Line Coupler with Valve by repa market
- **How much does it cost?** € 26.69 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.nl](https://www.desertcart.nl/products/504446575-repa-market-4-inch-100-mm-duct-backdraft-blockers-pipe)

## Best For

- repa market enthusiasts

## Why This Product

- Trusted repa market brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Durable & Reliable Build:** Robust male spigot and tough plastic housing built to last through years of ventilation cycles.
- • **Ultimate Backflow Defense:** Balanced damper blocks cold drafts, odors, and noise for a fresher, quieter home.
- • **Effortless DIY Installation:** No professional help needed—get your ventilation system upgraded in minutes.
- • **Versatile Multi-Duct Optimization:** Engineered for complex ductwork, from dryers to HVAC, ensuring stable airflow control.
- • **Precision Fit for Seamless Integration:** Exact 3.89 inch diameter and 1.18 inch depth for perfect duct compatibility.

## Overview

The Repa Market 4" Duct Backdraft Blocker is a precision-engineered pipe connector featuring a balanced damper to prevent backflow of air, odors, and noise. Designed for easy DIY installation, it fits standard 100mm ducts and is ideal for residential and commercial ventilation systems including dryers, HVAC, and kitchen extractor setups. Its durable plastic construction and male spigot design ensure long-lasting, reliable performance in multi-section ductwork.

## Description

Free delivery and returns on all eligible orders. Shop Repa Market 4" Inch / 100 mm Duct Backdraft Blockers - Pipe Connector with Backdraught Shutter - Backflow Preventer - Dryer Vent Adapter - Inline Air Extractor - Pipe Line Coupler with Valve.

Review: Stops the cold breeze - Simple idea but works very well. Stops the breeze comming through the ducting even on the windy days we've had
Review: Just what I needed - Mice simple device, installed and doing the job, star lost due to slower delivery time than promised...

## Features

- PRECISE DIMENSIONS: Insertion diameter: 3.89 inch / 99 mm Insertion depth: 1.18 inch / 30 mm Total width: 2.4 inch / 62 mm., this product offers easy do-it-yourself installation, ensuring hassle-free compatibility with your ventilation system.
- EFFICIENT VENTILATION: Engineered for reliable airflow control in bathrooms, kitchens, cooker hoods, and inline extraction setups — helps prevent cold drafts, odors, and outside air from entering through your dryer vent or duct system.
- ADVANCED BACKFLOW PROTECTION: Equipped with a pre-installed balanced damper that effectively stops unwanted odors, noises, and drafts from backflowing through your duct system.
- OPTIMIZED FOR MULTI-SECTION DUCTING: A critical airflow safeguard for long or multi-section ductwork, ensuring stable performance in ventilation, passive stack venting, air conditioning, positive-pressure systems, tumble dryer setups, HVAC installations, and air heating networks.
- DURABLE MALE-SPIGOT DESIGN: Constructed with a male spigot and durable white plastic housing, ensuring long-lasting performance in extractor fan systems.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B084BP47PT |
| Batteries Required? | No |
| Batteries included? | No |
| Best Sellers Rank | 16,389 in DIY & Tools ( See Top 100 in DIY & Tools ) 40 in Ducting |
| Colour | White |
| Customer Reviews | 4.1 4.1 out of 5 stars (364) |
| Date First Available | 30 Jan. 2020 |
| Included Components | Male Fit Connector with Suhutter |
| Item Package Quantity | 1 |
| Item Weight | 50 g |
| Manufacturer | Repa Market |
| Material | Plastic |
| Number of Pieces | 1 |
| Product Dimensions | 10 x 10 x 6.2 cm; 50 g |
| Shape | Circular |
| Size | 100mm |
| Special Features | Easy to Install |
| Usage | Commercial/Residential |

## Product Details

- **Brand:** Repa Market
- **Colour:** White
- **Connector type:** Coupling
- **Item dimensions L x W x H:** 10 x 10 x 6.2 centimetres
- **Manufacturer:** Repa Market
- **Material:** Plastic
- **Number of pieces:** 1
- **Size:** 100mm
- **Thread type:** BSP

## Images

![Repa Market 4" Inch / 100 mm Duct Backdraft Blockers - Pipe Connector with Backdraught Shutter - Backflow Preventer - Dryer Vent Adapter - Inline Air Extractor - Pipe Line Coupler with Valve - Image 1](https://m.media-amazon.com/images/I/21FaR60H02L.jpg)
![Repa Market 4" Inch / 100 mm Duct Backdraft Blockers - Pipe Connector with Backdraught Shutter - Backflow Preventer - Dryer Vent Adapter - Inline Air Extractor - Pipe Line Coupler with Valve - Image 2](https://m.media-amazon.com/images/I/21J+bXLdq-L.jpg)
![Repa Market 4" Inch / 100 mm Duct Backdraft Blockers - Pipe Connector with Backdraught Shutter - Backflow Preventer - Dryer Vent Adapter - Inline Air Extractor - Pipe Line Coupler with Valve - Image 3](https://m.media-amazon.com/images/I/21oX7bSiY4L.jpg)
![Repa Market 4" Inch / 100 mm Duct Backdraft Blockers - Pipe Connector with Backdraught Shutter - Backflow Preventer - Dryer Vent Adapter - Inline Air Extractor - Pipe Line Coupler with Valve - Image 4](https://m.media-amazon.com/images/I/31cc8oFm7ML.jpg)
![Repa Market 4" Inch / 100 mm Duct Backdraft Blockers - Pipe Connector with Backdraught Shutter - Backflow Preventer - Dryer Vent Adapter - Inline Air Extractor - Pipe Line Coupler with Valve - Image 5](https://m.media-amazon.com/images/I/31mCJ9FTY6L.jpg)

## Questions & Answers

**Q: Will drafts from outside open the flap?**
A: It is designed so that when installed correctly, the flap/door will be in a closed position and only able to be opened from one direction. So, to answer the question, no outside pressue will not open the flap (as long as it is installed correctly).

**Q: How tall is it?**
A: 4”

**Q: Is this to be installed on a vertical or horizontal run or both?**
A: Horizontal. It's own weight keeps it closed.

**Q: Can I use this to replace the cap where the dryer vent comes out of the house? Does it fit in the hole?**
A: It is just a gravity actuated valve like devise and is not designed for an exterior application. Rain, insects and rodents would be able to enter the dwelling through that simple valve.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Stops the cold breeze
*by M***N on 11 February 2024*

Simple idea but works very well. Stops the breeze comming through the ducting even on the windy days we've had

### ⭐⭐⭐⭐ Just what I needed
*by A***R on 16 October 2023*

Mice simple device, installed and doing the job, star lost due to slower delivery time than promised...

### ⭐⭐⭐⭐⭐ Good quality
*by A***R on 12 December 2025*

Excellent quality fast delivery

## Frequently Bought Together

- 4" Inch Duct Backdraft Blocker - Pipe Connector with Backdraught Shutter - Backflow Preventer - Dryer Vent Adapter - Inline Air Extractor Fan - Pipe Line Coupler with Valve
- AC Infinity Flexible 4-Inch Aluminum Ducting, Heavy-Duty Four-Layer Protection, 8-Feet Long for Heating Cooling Ventilation and Exhaust
- 4" Inch Plastic White 3 Way T Joints - Duct Splitter for Exhaust Fan Dryer - Round Duct Hose Connector - Vent Air Pipe Joint - 90 Degree Three Branch Junction

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**Shop now:** [https://www.desertcart.nl/products/504446575-repa-market-4-inch-100-mm-duct-backdraft-blockers-pipe](https://www.desertcart.nl/products/504446575-repa-market-4-inch-100-mm-duct-backdraft-blockers-pipe)

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*Product available on Desertcart Netherlands*
*Store origin: NL*
*Last updated: 2026-01-27*