Amazon.com: Replacement A-Coil Filters Compatible with Nordyne C8DAM01830U-B, 921784, and Many Nordyne/Intertherm Models - 15" x 17" x 1/8" - 2-Pack : Appliances
Foam Mobile Home Furnace Door Filter for Miller, Nordyne, Intertherm, – Filter Everything
Amazon.com: Intertherm Furnace Filters
Coleman/Evcon Foam Filter 1/4" x 19" x 36" For Mobile Home/RV Furnaces (7660-3401) - H & S Mobile Home Supplies