IPhone 3.5mm 4C Plug Connect Cable for Intercom AUX Port can connect your iPhone to your intercom's rear AUX Port for making and receiving calls. This cable also serves as a music cable, allowing music streaming into your intercom. However, the music volume will not be automatically attenuated with intercoms that have VOX. For music volume attenuation with VOX intercoms, use #CS-MUSIC connected to the 3.5mm input port. This cable is exclusive to iPhones, some other cell phones, and select satellite phones.