Questions and Answers for Pamlico Air 20 in. x 20 in. x 1 in. Fiberglass Furnace Air Filter, MERV 1

A:  If you stretch out a pleated filter it has twice the surface area then a flat filter which is why I prefer pleated but only use pleated with a wire wrap instead of a cardboard wrap because wire is less restrictive.

A:  NONE

A:  Yes!

A:  Usually 12

A:  Hello Jill, Thank you for your recent inquiry with The Home Depot. Our available air filters by size specific can be found here on our website https://www.homedepot.com/b/Heating-Venting-Cooling-Air-Filters/N-5yc1vZc4kw We appreciate your business and look forward to serving you in the future.