Appliance Parts and Supplies Dundas Jafine Recessed Dryer Vent Box For 4" Dryer Duct DRB4XZW Dundas Jafine's Recessed Dryer Vent Box allows the dryer to be pushed up against the wall of the laundry room instead of having to be positioned 5" - 6" away in order to accomodate the dryer duct. The box also completely protects the duct from being crushed and lint build-up is minimized due to the limited kinks and bends. The Dundas Jafine Recessed Dryer Vent Box is made of high impact polystyrene (UL94HB rated) and has some additional features and benefits which make it unique over other dryer box products in the market. This product has a built-in draft blocker to help reduce cold air backdraft into the home as well as an oval to round duct adapter which threads on easily to the duct and makes installation fast and easy.