Exclusively engineered for use with the Mr. Heater Portable Buddy Heater, Model MH9BX. Compatible only with single-tile Buddy units manufactured after 2009. This fan accessory is not approved for use on any other heating appliance. Do not install or operate on models MH18B, MH12HB, MH12B, DXH12B, MH4B, or MH4BC.​ Self-Powered Air Circulation: Uses thermoelectric technology to convert heater-generated heat directly into fan power. No Batteries Required: Operates entirely without batteries or external power sources for maximum convenience. Easy Compatibility: Specifically designed to fit all MH9BX Mr. Heater Portable Buddy Heaters. Improved Heating Efficiency: Quietly distributes warm air, enhancing comfort and warmth in any space.