This Suburban Manufacturing Furnace Blower Wheel Door is compatible with the SF Series. Specifications•Compatibility: Suburban Furnace SF-20/ SF-25/ SF-30/ SF-35/ SF-42/ SF-20F/ SF-25F/ SF-30F/ SF-35F/ SF-42F Built To Match Your Exact Requirements Reliable Performance & Longevity | Suburban Mfg Furnace Blower Wheel