Kair Airbrick Grille with Damper Flap for 150mm x 70mm Rectangular Ducting External grille dimensions: 221mm x 80mm. Spigot Size: 146mm x 65mm . Fits inside 150mm x 70mm rectangular ducting pipe DUCVKC604 flat channel. The spigot on the back is 146mm x 65mm therefore both straight pipe (Female fittings) and connector bends (Male fittings) will fit over the spigot. Static Pressure Drop in Pascals: 15 l/s: 23.66 Pa - 30 l/s: 44.40 Pa - 60 l/s: 100.39 Pa. Free Area: 4,114 mm2 Suitable to use in compliance with Part F Building Regulations. Max / Min Temperature: +60c / -15c. Kair 100% Satisfaction Guarantee. The performance and dimensions of the Kair ducting range makes it ideal to use in Kitchens and Bathrooms, where duct runs can easily be concealed above units or ceiling voids. Perfectly suited for ducting your bathroom or kitchen extractor fan, hydroponics, in-line extract fan, tumble dryer, or cooker hood. This air brick can be used as a part of a long ductwork run for a variety of purposes including whole house ventilation, passive stack vent, air conditioning, HVAC, and Heat Recovery Systestems. Compatible with the extensive Kair ducting range of fittings, outlets, and grilles. For the full range of compatible products please search for Kair Ducting in the search bar. Also fits other ranges. If you have any questions please do not hesitate to ask fellow purchasers via the Customer Questions & Answers system below.