The FSE electric fan convectorss are made in 5 sizes, with heat outputs from 3 to 8.5 kW. The electric heat exchanger has two-stage sealed electrical resistance made of finned steel tubes to allow part-load operation. The power supply is three phase, 400 V - 50 Hz. The first two sizes (up to 4.5 kW) can also be supplied in the single-phase version. As standard they are fitted with two speed control, room thermostat and button for electric heater part-load operation.