20" X 20" Aluminum Insulated Fire Resistant Access Panel Door For Wall / Ceiling Application (Lock and Key) With Frame - [Outer Dimensions: 21" Width X 21" Height] RV Mobile Home you can attain the diameter

you can attain the diameter of the vent

Actual Filter Size – 31 3/4"w x 21 3/4" x 1"

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

9% pure copper)

20" X 20" Aluminum Insulated Fire Resistant Access Panel Door For Wall / Ceiling Application (Lock and Key) With Frame - [Outer Dimensions: 21" Width X 21" Height] RV Mobile Home you can attain the diameter+ Product Details Size 20" X 20" is the size for the drywall opening measurement only, actual front end outer dimensions are 21" width X 21" height High Quality Strong and sturdy aluminum built to last. Design Aluminum material & color to give your space an attractive look & provide high durability corrosion protection no rust. Built in tumbler lock and key is provided Easy Access Provides easy access for HVAC, plumbing, electrical, crawlspace etc.