 It is the NRF 52-840 Sensor Board. This is also known as the LED Glasses Board because it was originally released to drive our LED glasses. This is an incredibly cool dev board for all kinds of wearable projects and remote projects. It has Bluetooth, BLE capability. You can use that for things like Bluetooth MIDI, Bluetooth HID. It has an accelerometer on it so you can do tilt kind of stuff. I've got my little phone there that's listening over Bluetooth to what I'm doing with this neat little package. I've got a little LiPo battery under there. I am using the accelerometer and that's actually turning one of the knobs. Listen to it as I move the fader. Little add-ons we want using I squared C and you can chain them so you can have a bunch of stuff. I thought this was really cool to consider this board as just a dev board and not worry about the glasses part of it. NRF 52-840 Sensor Board, aka LED Glasses Board.