The Shenoy Audio 220Ω Headphone Impedance Adapter enables you to use the ANC feature of the ELEVATE SH025 without powering on the headphones. It is also also suitable for wired connections with high power audio devices such as amplifiers. The adapter comes in a standard 3.5mm (1/8 inch) TRS 3 Pole format with a male plug on one end and a female adapter on the other end.