Plug: RJ9 Crystal Head. Scope of Application: Used for Devices with RJ9 Headphone Jack. Voice Coil Impedance: 150±15Ω (at 1kHz). Current Consumption: 100-500µA. [Flexible And Durable] The headphone adopts a sturdy structure and material design to ensure super performance and make it durable, the long cord allows you to move more flexibly.