Line Selector

The HotShot ABi makes it easy to select between two balanced inputs on stage, with a single latching footswitch to toggle from one source to the other. This allows an artist to switch between two dynamic microphones during a performance, freeing up input channels on your mixer. The latching footswitch also opens the door for other useful applications, including using the ABi as a mute to turn off a microphone, select between two wireless receivers, or switch between two mono playback devices.

https://www.radialeng.com/product/hotshot-abi