12" X 4" [Duct Opening] 1-Way Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 13.75"W X 5.75"H] Supply Grille + Product Details Size -

+ Product Details Size - 28"w X 12"h is the size for the duct opening measurement only

For 8" duct opening

1-1/8" - 2334 PSI

This Thermostat from Bramec will fit almost any thermostat

+ Product Description Protect and secure your thermostat with this high-quality Clear Plastic Thermostat Guard

12" X 4" [Duct Opening] 1-Way Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 13.75"W X 5.75"H] Supply Grille + Product Details Size -+ Product Details Size 12"w X 4"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 13. 75" width X 5. 75" height. High Quality High quality steel with counter sunk screw holes (screws included) and no sharp edges. Equipped with a lever for easy airflow adjustment and dampening. Airflow Control Adjustable airflow lever allows precise control over the direction and volume of air. Installation