Samsung Free Joint Multi (FJM) Air Conditioning systems are designed to be flexible – allowing you to heat or cool multiple areas in your home from the one air conditioning system. An FJM System consists of three main components: an outdoor unit, compatible indoor unit(s) and a controller.* The flexibility of our FJM systems means that you can have up to 5 indoor units connected to a singular outdoor unit. They are compatible with a variety of indoor types, so you can choose the combination that suits you best. You can also set different temperatures on each indoor unit.