Important Notes 1. We don't recommend to use the 3.5mm port and RCA port on the item at the same time, because it may affect the sound quality. 2. To ensure proper hardware detection, we recommend to plug the external headset into the adapter first, then connect this USB sound adapter to the computer or mobile device. 3. Mono Microphone requires a 3.5 TRS connector (not TS or TRRS). Product Description  Ugreen USB Audio Adapter includes a stereo headphone output jack, left & right audio output and a mono microphone input jack. It can bypass the defective sound card or the faulty 3.5mm audio port of your laptop/desktop system and regain the audio function. Save the cost of replacing a failed sound card. Some laptops or ultrabooks only combine headphone and mic into one 3.5mm audio jack. With this USB audio adapter, traditional headset can still be used on laptops. More Connection Options for Audio Output Compared with other adapters in market, it offers you 2 options for audio output, 3.5mm aux and 2RCA, which makes it compatible with more external speakers. Specifications Input: USB 2.0 A Male, 3.5mm mono microphone jack Output: 3.5mm stereo jack, L/R RCA audio Plug and play Support sampling rate 44.1K/48K/96KHz and bitrate 16/24 bits - Frequency Response: 20Hz-20kHz, Output Power: 30mW, SNR: 92dB Dimension: L70xW55xH22 (mm) with 1m/3ft cable. System requirements Windows 10/8.1/8/7/Vista/XP and All latest version  Mac OS 8.6 or above Configuration Instructions Windows: Right-click on the sound icon in the taskbar; Select Playback or Recording devices; Adjust the volume on the computer and in the application. Mac: Go to System Preferences > Sound >C-Media USB Headset >Output or Input >Volume Package Content 1 x Ugreen USB Stereo Audio Adapter