The Flushmount Pro is our flush mount beauty. Once installed this shows no rim just the rectangle air flow opening. Form and function can be seamlessly integrated. A virtually invisible option that blends into any surface. Must be installed at the sub-floor level prior to flooring (or surface) installation. Use for supply air registers found on floors. Can also be used walls and ceilings that have different surface materials (like: tile or shiplap). Use with ANY surface material hardwood vinyl laminate carpet tile Lego you name it. *Material must be between 1/8 and 7/8 thick. Install is best done by a Pro. Must be mounted before flooring is installed.