Minhe 4-Inch Duct Return Air Blocker – Backflow Preventer With Damper For HVAC, Dryer Vent, And Kitchen Exhaust Systems

About This Product

If cold drafts, weird smells, or noise from your ductwork are bugging you, this Minhe return air blocker is a simple fix.
It’s designed for 4-inch (100mm) diameter ducts – the standard size for a lot of home ventilation systems – and it blocks backflow so air only goes one way: out.
That means no more cold air sneaking in through your dryer vent or kitchen exhaust when they’re not running.

It comes with a pre-installed balanced damper that does the work automatically – no fiddling with settings.

This thing works for bathroom fans, kitchen hoods, dryer vents, and HVAC air returns – pretty much anywhere you’ve got a 4-inch round duct.
It’s made from sturdy white plastic that’s built to last, and the damper operates smoothly without sticking or jamming.

So if you’re tired of outside air leaking in or weird noises traveling through your vents, this little gadget is a cheap, effective solution.

Product Information