Pictured below is the standard 3.5mm headphone jack that is compatible with all airtube headphones, handsets and other plug in audio solutions. If your phone doesn't have this port you will need an adaptor. The adaptors for sale in this listing are high quality two-way adaptors. A two way adaptor enables the user not only to listen to sounds but also to produce it via a microphone. This is necessary for mobile phones and voice conversations etc.