A power device is provided for filtering or dampening harmonics and optimizing the power factor in power distributions systems. A device for a 3-phase power system comprises series inductors able to communicate between an AC power source and a non-linear load. Connected in parallel to the series inductors, at the junction with the non-linear load, are shunt inductors used to trap harmonic currents. Power factor correction capacitors are connected to the ends of the shunt inductors. The series inductor and shunt inductor are used to form a coaxial reactor assembly, which further comprises a reactor core. The coaxial reactor assembly is formed by winding a first inductor around the core and then winding a separate second inductor around the perimeter of the first inductor. In another embodiment, the device includes a third inductor to achieve better dampening and power factor performance.