 It is the five port Stema QT hub. It is a passive hub. It allows you to create a bunch of I squared C devices plugged into a single microcontroller board without needing to run from sensor to sensor to sensor and create a humongous chain of them, which is pretty darn cool. So here you can see I've taken the hub and then I have these four sensors plugged into it and then the fifth item plugged into the hub is my QT pie right there. So here I've got an accelerometer, a pressure sensor, a temperature and humidity sensor, and a magnetometer. So I can read the values on all of those over a single I squared C bus. They all have their own unique addresses, but as far as the actual wiring of the thing, it's really nice and neat with that little hub right in the middle there. So I'm just using some nylon standoffs and screws and nuts there to hook that all together. It is the Stem-A-Q-T and quick five port hub.