Fonus(TM) brand Headset Adapter. Adapter allows connection from 2.5mm to any 3.5mm stereo headphone and portable speaker. * 2.5mm Female to Smartphone 3.5mm Male. On/off button enabled (if your device supports on/off feature). It supports Microphone (If your device has a microphone feature). Stereo-channel enabled if your 2.5mm headset is stereo enabled too.Sleek design made to fit comfortably. * 3 rings jack. Reduce Electromagnetic Radiation (EMR) caused by cell phones and bluetooth headsets by using a wired headset.