Have you even experienced the hardship of connecting your cables in case your computer is placed under your table and you want to listen to the music? When you connect the Microphone ad the speaker simultaneously, you may hear the screaming noise. All connections can be easily done when you have this Audio Switch Box; No more interference. Multiple audio devices can be integrated; such as earphone, speaker, microphone, etc. Easy to use; cables can be conveniently connected. Earphone, speaker, microphone can be switched easily No peak frequency noise even speaker and microphone are simultaneously connected. Volume can be controlled conveniently. How to use: Connect the Green jack of the Audio Switch Box to the Audio Out (Green Jack) of your computer. Connect the pink jack to the Microphone (Pink jack) of your computer. Insert the USB plug into the USB port on the computer (ASB3 only). Pug in the speaker, earphone, or earphone/microphone into the Audio Switch Box. Audio Output for External Speaker.