The Sony WH-CH520 wireless headphones do not have a 520-ohm impedance rating; their actual impedance is typically specified around 32 ohms when active or driven wirelessly.Specifications OverviewImpedance: 32 ohm as stated by FullSpecs.net.Battery Life: Up to 50 hours of playback.Driver Unit: 30 mm dynamic drivers.Connectivity: Bluetooth Version 5.2.