Female Side is mmcx plug: This convert is worked for mmcx cable connected with Etymotic ER4P Earbuds. Male Side is for Etymotic ER4P: This adapter earbuds side is compatible for Etymotic ER4P ER4B ER4S ER4PT ER6I Earphone.If you have any issue abouth other earbuds models,please contact us to make sure details. Audio Unchanged: The adapter is small and convenient. This DIY adapters are great for modding hobbies, provides your personal sounds.The deliver sounds are lossless sound quality.Join us to create more DIY. Many Types: We also have many other types adapters which can help you to resolve the different cables connected to different earbuds.Let you enjoy the DIY HiFi life.Provide more possibility. Our after-sales: If you have any issue or idea about our products,please feel free to contact us.We will provide the best solution for you.We not only provide high quality product,but also with high after-sales service. OKCSC MMCX (Cable Side) to ER4P ER4B ER4S ER4PT ER6I(Earphone Side)Adaptor Compatible for Etymotic Series Earphone Transparent