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.