MRCOOL 20 KW Universal Air Handler Heat Strip with Circuit Breaker - MHK20UMRCOOL 20 KW Universal Air Handler Heat Strip with Circuit Breaker MHK20U Provides Emergency Heat for your MRCOOL Universal Air Handler. MRCOOL is the compatible heat kit model for MRCOOL MDUI18048 and MDUI18060 is capable of 65,001 70,000 BTU of heating capacity to keep you comfortable through the winter months. FEATURES: MDUI18024 is compatible with the 5 kW, 8 kW and 10 kW heat kits MDUI18036 is compatible with the 5 kW, 8 kW and 10 kW heat kits