For powering phantom powered microphones with either 12VDC or 48VDC. Since the units use a 100KHz switching power supply there is no audio noise generated. They have output pull down resistors so they will work with any mixer and have 2DC jacks so several units can use one adapter. The PB223 powers two microphones. Specifications: Phantom voltage: 12V or 48V selectable Jacks: Male and Female XLR 2: 5mm DC input jacks Control: 12/48 volt selector switch Power Input 14 - 18 VCD (included) Size: PB223: 6" x 2.5" x 1.25" Weight: PB223 - 1.5 lbs. (.68 Kg)