 It is the LED arcade button one by four board. Imagine hooking up arcade buttons before this. It was a lot of wiring. You have four wires per button with these lighted buttons because you've got the switch and you've got the LED. This drives the LEDs with PWM. This reads the switches. So the seesaw chip takes care of all the digital I.O. on this board. And then it just is receiving and sending messages back and forth to your microcontroller over STEMA QT. I have this here. This is a little button box. I've connected them up to another of these arcade button boards and then I just have my little STEMA QT cable running there. When I press any of these buttons here, we get them to light up and the first set, those are still working as well. It is the LED arcade button one by four STEMA QT based seesaw board that requires no soldering to hook up your lighted arcade buttons to your project.