This versatile bi-directional cable is compatible with both 3.5mm audio-out and audio-in ports. It allows you to connect AirPods Max or Beats Solo Pro headphones to 3.5mm audio sources and iOS or iPadOS devices to speakers with 3.5mm audio ports. Simply plug your headphones into the audio-out port of your device, or connect your Apple device to a speaker using the audio-in port. This cable offers convenient flexibility for a range of audio connections.