Analog switches are a solid state alternative to relays, when you want a smaller, lower-power technology that won't wear out mechanically. And, as the name implies, you can use the Adafruit ADG728 1-to-8 Analog Matrix Switch to connect between eight analog signals, much like a set of 8 mechanical switches. These chips tend to be tiny surface mount parts, so this breakout will let anyone use the ADG728 switch for signals up to 5V, without fiddly soldering.The ADG728 uses I2C to select which of the 8 channels switches to turn on or off, to connect that channel to the single analog 'D' pin Note that unlike digital switches and multiplexers, these are not 'input' and 'output' because the signal is bidirectional. You could have the D signal be an input to 8 outputs, or the 8 inputs to one output.