This is a snap fit case designed to fit the CarLoop CanBus Adapter with a Particle Photon connected. It has a slot for connecting a USB cable to the Photon for programming and debugging. It also has a 3mm hole where the Status LED on the Photon is. You can cut a small piece of clear or frosted 3mm filament and put it though the hole to act as a fiber optic transfer of the LED status. Took 6 prototypes to get it just right. Please leave feedback.