This is a controller for our Mbot 3d printer. It is a derivative kit of MakerBot Gen4 Interface Kit.Have the same function. We use it to control the SD card printing or test our machine.You can find it from http://www.mbot3d.com/products/lcd-interface-controllerThere is a power led and a debug led in the front.You can tuneup the lcd display, you will find a hole at the back of controller. Use screwdriver to tune the light of lcd.