Kit required for conversion of AC electric units with a 2" vent stack and an AC heater. Converts the AC powered unit to operate off-grid without AC power as well. An additional 4" vent stack with a 12VDC vent fan is included. The AC fan and the heater should only operate when connected to shore power, utility power, or generator power. The 12VDC fan can be connected to your battery bank in an off-grid power system.