HTC SC5310 Mini-USB Headset Adapter (Mini USB to 2.5mm and 3.5mm and Mini USB) - Original OEM - Non-Retail Packaging - Black 2 Mini USB Ports 2. 5 mm stereo headset jack 3. 5 mm stereo headset jack Mini to mini USB connectivity This adapter features one 2.5 mm headset port, one 3.5 mm headset port along with two mini USB charging ports