IRSTBL 4 Inch Backdraft Damper – One Way Airflow Valve for Ducting, Stops Cold Air & Draughts – Galvanised Steel Vent Insert, 100mm

• Prevents Reverse Airflow: One-way spring-loaded valve stops cold air, odours, and backdrafts from entering through ventilation ducts or extractor fans.
• Reliable Airflow Control: Precision-balanced aluminium flaps open smoothly with outgoing air and close tightly against incoming currents to maintain room temperature.
• Durable Metal Construction: Galvanised steel body with corrosion-resistant finish withstands heat, moisture, and daily HVAC system use for long-term reliability.
• Noise-Reducing Dual Gaskets: Foam seals on both sides absorb vibration and ensure a quiet, leak-free fit in dryer vents, range hoods, and bathroom fans.
• Quick Push-Fit Installation: Designed for standard 100 mm (4-inch) round ducts; simply insert into the pipe for a secure, airtight seal — no extra tools required.

Keep airflow moving in the right direction with the IRSTBL 4-Inch Backdraft Damper. This durable galvanised steel one-way airflow valve prevents cold drafts, odours, and reverse airflow in your ventilation system. Its spring-loaded aluminium flaps open automatically with outgoing air and close securely when the flow stops, ensuring efficient one-way performance in HVAC ducts and extractor fans. Built for long-term reliability, the corrosion-resistant metal body withstands heat, humidity, and daily use. Dual foam gaskets cushion movement, reduce vibration noise, and maintain an airtight seal for consistent ventilation efficiency. Designed for standard 100 mm (4-inch) ducts, the damper installs easily with a simple push-fit connection — no additional tools required. Suitable for use in bathrooms, kitchens, dryers, and general HVAC systems.