The MRCOOL MLP1SH Signature Series High Altitude Single Stage Gas Furnace Propane Conversion Kit is an HVAC accessory designed to convert compatible MRCOOL Signature Series single-stage gas furnaces from natural gas to propane operation in high-altitude environments. It works by modifying the furnace’s fuel delivery components to maintain proper combustion and heating performance unde... https://www.partshnc.com/mrcool-high-altitude-propane-conversion-kit-mlp1sh