A flush mount floor register sits flush with a 3/4" hardwood floor. It is designed to lay flat with the surface of the wood flooring, provides two-way diffusion, and is the preferred style for sand and finish hardwood floors where an architecturally smooth look is desired. Each frame is grooved on the outside to accommodate most 3/4" tongue and groove flooring. It is recommended that this floor register be installed during the installation of your hardwood floor, while its use in high-traffic areas is not recommended.