This is the type of switch you often find used as the pickup selector on electric guitars. The lever clicks through five different positions so you can select from three different inputs and a combination thereof. While this is, strictly speaking, a selector switch (albeit a switch with some strange permutations) It’s also very useful as an encoder and by connecting it to a microcontroller you can read five discrete positions from three GPIOs. Check out the connection diagram below for details.
Note: Colors may vary. The PCB may be blue or green and the knob may be black or white. Functionality and specifications are identical, however.