Five minutes to fit, stopped weeks of noise from a constantly flapping vent. The Blauberg external vent, in a colour to match the house bricks, is a masterpiece of design. Larger than the standard vent that comes with extractor fans, the fixing holes can be drilled, sufficiently away from the 112mm hole drilled in the fabric of the property, not to worry about the bricks fragmenting when the screws are fastened. Its large enough for air ingress egress and is weather resistant with the curved shroud. The foam backing sealed the masonry, keeping insects from getting behind the fitting. A small amount of sealant on the outer edges of the backing plate against the masonry sealed it,but that was my personal choice. An excellent product.