Input: 3.5MM for headphones or earphones. Output 1: 3.5MM for headphone jack on computer/laptop. Output 2: 3MM for microphone jack on computer/laptop. Connect stereo headphones and microphone to both your computer's audio port and microphone port. Compatible with laptops, cell phones, desktop computers and other devices via a 3.5MM audio jack. Clear sound quality, shielded design, shielding anti-interference, presenting a better sound quality effect. Better sound quality with less loss. One can be used for microphone input connection and the other for connecting external speakers. To ensure proper hardware detection, plug your external headphones into the adapter before connecting the adapter to your computer or mobile device.