The audio adapter is designed for the HTC Droid DNA:
HTC Droid DNA
If you prefer to use a 2.5mm headset with your HTC Droid DNA cell phone, you will need to plug in the 2.5mm audio adapter in order for the headset to work. Just plug this audio adapter into your cell phone to convert the audio. This adapter allows you to use a 2.5 headset with your HTC Droid DNA phone.
Easily installs; simply plug the audio adapter into your HTC Droid DNA cell phone audio jack; then plug in any 2.5mm, two ring headset into the audio adapter
Currently offered on: Verizon
All carriers including Alltel/ AT&T/ Sprint PCS/ T-Mobile and Verizon are trademarks of the respective companies
"We are your one stop shopping spot for a complete selection of products for your cellular phone"
Original HTC Droid DNA Hands Free 2.5 Audio Adapter