18 x 12 Merv 2 HVAC Pleated Filter, 12-Pack Sheet Metal/Adjustable Elbow this robust access door ensures

this robust access door ensures security with its tumbler lock mechanism

+ Product Details Size - 12"w X 36"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 30" x 20" OR 20" x 30" duct opening (measured at the opening)

+ Product Details Size – 32"w X 34"h is the size for the duct opening measurement only

Actual Front End Outer Dimensions Are 14" Width X 8" Height - SEE IN DESCRIPTION HOW TO MEASURE A GRILLE

18 x 12 Merv 2 HVAC Pleated Filter, 12-Pack Sheet Metal/Adjustable Elbow this robust access door ensures+ Product Details Size 18"w X 12"h pleated MERV 2 filter for HVAC return filter grille 12 Pack. Actual dimensions: 17. 75" X 11. 75" High Quality A uniquie combination of cotton & synthetic fibers gives you the most filtration and the least air resistance equals great air & easy airflow for your system Design The W shaped pleats increase the surface area, effectively capturing dirt and particles such as pollen, dust mites, standing dust, spray paint