3.5mm Headphone Adapter is the must-have item for all iPhone (1st generation) users. Lets you connect your favorite headphones into the recessed headphone jack on your iPhone (1st generation). Simply attach the plug end into headphone jack of your iPhone and plug in your favorite headphones in the other end. With the 3.5mm Headphone Adapter, you can listen with any 3.5mm headphone, earphone, headset or external speakers. Suitable for Apple iPhone or any digital audio device with a 3.5mm headphone jack. Adapter cable measures 4.5 inches (11.5cm)