8" Insulated Aluminum Flexible HVAC Duct R-4.2 – 25' Length Color_White if your hole is 20"

if your hole is 20" wide by 14" tall

+ Product Details Size - 28"w X 6"h is the size for the duct opening measurement only

angle the louvers up for efficient cooling

+ Product Details Size - 18"w X 18"h is the size for the duct opening measurement only

HVAC Premium has been providing superior quality service for many years

8" Insulated Aluminum Flexible HVAC Duct R-4.2 – 25' Length Color_White if your hole is 20"+ Product Details High Quality Aluminum housing on the outside and on the inside for the best insulation value Insulation A thick blanket of fiberglass insulation provides you with an R Value of 4. 2 Energy Efficient Air tight inner core decreases the pressure loss and provides a more hygienic environment high energy efficient No fiberglass erosion into air stream Design Designed to withstand bends and sharp turns without kinking. Tough reinforced