Pack of 2 Cold Air Blocker Flaps - 4-inch Non-Return Valve Damper to Connect Duct Pipe or Flexible Hose - Prevent Backdrafts and Drafts

• You will receive a pack of 2 x 100mm / 4 inch plastic ducting connectors with inline backdraught shutter / gravity damper flap. Material: PVC plastic. Colour: white. Diameter: 100mm.Prevent cold air from entering through home exhaust fan ducting using back draught shutter.
• Efficient Airflow Control: Features of 100mm backdraught shutter flaps, designed to effectively prevent backdrafts and maintain optimal airflow in duct systems.
• Universal Compatibility: Suitable for connecting with 4-inch duct pipes or flexible ducting hoses, ensuring a snug and secure fit for a variety of ventilation setups.
• Durable Construction: Crafted from high-quality materials, these shutter flaps offer long-lasting performance and resistance to wear, making them ideal for both commercial and residential use.
• Easy Installation: Designed for hassle-free setup, these non-return valve dampers can be quickly and easily installed without the need for professional assistance.
• Cold Air Stopper: Acts as an effective barrier against cold air intrusion, maintaining indoor temperature and energy efficiency, especially during colder months.

Designed for ventilation systems in residential and commercial buildings Ensures one-way airflow, preventing air from flowing back for optimal freshness Compatible with 100mm / 4-inch pipes and flexible hoses Male spigot fits into 100mm round pipes and 102mm flexible hoses, facilitating easy connection of duct lengths Effectively blocks unpleasant odors, noises, and drafts from returning through the duct Features a gravity flap mechanism, eliminating the need for fragile springs Ideal for preventing odor backflow in ducting systems or when multiple extractor fans are connected Round rigid ducting offers superior airflow performance compared to rectangular or flexible alternatives Pressure drop measurements: 15 l/s = 25.0 Pa, 30 l/s = 44.90 Pa, 60 l/s = 101.60 Pa Simple push-fit installation for convenience and durability Constructed from high-quality white Polystyrene/Polypropylene plastic for longevity Temperature range: +60°C to -15°C Compliant with Part F Building Regulations for safe and effective use