Return Air Boxes/Plenums Side Entry + Fresh Air Spigot

Also available in 10mm rubber. For cost, add 20% to 5mm price.
Example
Example Box Size: 900 x 400
Formula: 900 + 900 + 400 + 400 = 2600
Perimeter Range: 2401 – 2900
NOTE:
To select the correct product code from the table above for a specified box size, you must firstly calculate the perimeter of the box as shown in the example above which will determine the correct perimeter range to choose from in the table above.
If a specified box exceeds the perimeter it will be priced on application.
If box is required to be stepped there will be an additional charge of $15.00 ie:- that is if the spigot size does not fit the specified box.