10" x 10" [Duct Opening] Ceiling Supply Diffuser Vent Cover – 2-Way Airflow with Full Aluminum Frame, Back Blades & Opposing Blade Lever Damper [Outer Size: 13" x 13"] 16in diameter + Product Details Size –

+ Product Details Size – 28"w X 20"h is the size for the duct opening measurement only

+ Product Description Protect your thermostat with the durable and tamper-proof Beige Metal Thermostat Guard

High quality – high quality solid stamped steel with counter-sunk screw holes (screws included) and no sharp edges

+ Product Details Size – Duct end cap is 20" X 12" | 26-gauge galvanized steel end cap

10" x 10" [Duct Opening] Ceiling Supply Diffuser Vent Cover – 2-Way Airflow with Full Aluminum Frame, Back Blades & Opposing Blade Lever Damper [Outer Size: 13" x 13"] 16in diameter + Product Details Size –+ Product Details Size Refers to duct opening only. The face frame extends roughly 1. 5" on each side. Do not measure the overall grille for sizing. Design All aluminum frame and back blades. Rustproof and built to last in moisture prone environments. Quiet Airflow Opposing blade damper design reduces vibration and noise for smoother air distribution. Clean Finish White powder coated surface resists chips, scratches, and discoloration over time. Easy