This simple but effective enclosure will fit any 'classic Arduino' shaped development board - we've tested it for sure with the Arduino UNO R3, Adafruit Metro, and Adafruit Metro Express. It's clear so you can see all your onboard LEDs and silkscreen labels. There are four small screws you can use to affix the board and some bumpers that go on the bottom. We rather like this case because it's low-profile enough that you can fit shields on top. There's even a flexi-nub for pressing the reset button!