Many cell phones do not use a standard headset jack (3.5mm) and you are forced to use their original 2.5 mm earphones. This adaptor enables your headset to use a standard earphone jack to get full stereo sound from. This product provides high-quality audio output and allows you to plug in any stereo device that has a standard 3.5mm audio jack, such as your favorite pair of headphones. It comes with a standard female 3.5 mm jack on one end that converts to a 2.5 mm male jack on the other end. Now with this original Cellet stereo audio adapter, you can listen your favorite music. You can use your favorite 3.5 mm headphones with your 2.5 mm enabled device. It is simple and easy to adapt your phone to get the most out of your music. This is Perfect for listening MP3 songs with your own earphones, speakers etc.