This adapter compatible for all type of no mic function earphone. If your earphone/headphone with Mic Function,please check it is OMTP Standard Jack or CTIA Standard Jack, as this adapter only suit for OMTP Standard Jack Earphone but not compatible for the CTIA Standard Jack Earphone. 3.5mm Female to 2.5mm Male Adapter provides stereo / mono functions to convert 3.5mm audio. Your music keeps playing even during your toughest workouts. Connect your phone to your Hi-Fi System via a 3.5mm Audio Cable. Enables your phone to use other 3.5mm plug handsfree to listen to radio or MP3 (depends on your phone's compatibility). Gold plated connectors resist corrosion and ensure optimum sound quality. The slim design makes this the best style to use, there are no extra cords or odd angles, just plug and go.