Features: Made of Decorative Plated Metal Heavy Gauge Steel is 88% heavier than other brands, (14 oz vs. 7.6 oz). Comes with an adjustable abs resin rustproof Damper Box that will allow full air flow with no rattling. Click the link below to visualize how a floor register will look in your floor. How a Floor Register Sits in your Floor Common Floor Register Sizes The chart below details the most common floor opening sizes and the size of the registers that fit in them. All of our registers are measured based on the opening size of your floor. All sizes below are not available in all styles. All sizes approximate. Floor Opening Size Register Size (W x L) 4" x 10" 5 1/2" x 11 1/2 4" x 12" 5 1/2" x 13 1/2"