"All vent cowls and flaps are noisy, clattering and banging in the wind. I have stuck a single tiny square of foam draft strip as a bump stop for the flap. It reduces the bang to a soft thump, but more importantly, it has reduced the frequency of banging. because it lets a tiny bit of air through. After al,l it seems to be best of the bunch for reducing drafts. Just off to buy another to replace clattering flaps."
"Good solid overall construction as you would expect from Manrose. As someone else had mentioned, the flap is secured and opened on two small lugs on the opening plate. This is the 3rd replacement I have had due to the lug/s breaking off. Marked down for features as other cowls have split or dual flaps rather than a single. Performance - okay, works well enough when its not broken"