The voltage stabilizer isolates devices sensitive to voltage variations and/or interference. It ensures a constant voltage at its output, while being galvanically isolated (the ground between the inverter input and the inverter output is isolated).
It is placed at the output of batteries and can accept a variable input voltage range. These stabilizers are available in two power ratings (100 Watts or 250 Watts). Some models also act as voltage converters (12 Volts to 24 Volts or 24 Volts to 12 Volts).