20" X 20" Sound Rated Steel Access Panel Felt Covered Door For Concealed Wall / Ceiling Application With Slotted Lock - [Outer Dimensions: 21" Width X 21" Height] rg1010 + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 10" x 36" or 36" x 10" duct opening (measured at the opening)

+ Product Details Size - 26"w X 8"h is the size for the duct opening measurement only

875" width X 13

+ Product Details Size – 16" x 28" or 28" x 16" is the size for the duct opening measurement only

20" X 20" Sound Rated Steel Access Panel Felt Covered Door For Concealed Wall / Ceiling Application With Slotted Lock - [Outer Dimensions: 21" Width X 21" Height] rg1010 + Product Details Perfect Fit+ 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 High grade steel construction. Design 1mm galvanized steel material with sleek, shiny, durable white powder coat finish for an attractive look & high durability corrosion protection 15mm medium density fibreboard with felt cover and rubber sealing between the door and frame for tight security.