The 2.5mm to 3.5mm adapter allows you to use normal 3.5mm headphones with a range of PDA and phone devices. Once inserted into the device s 2.5mm headphone socket, you can plug in your favorite 3.5mm audio headphones. Special Features: 3.5mm Female to 2.5mm Male Use 3.5 mm Headphone on 2.5 mm device Stereo Sound