This thingy is a replacement part for the Monoprice Dual Extrusion 3D Printer. It can also be used on the Makerbet Replicator 2. It replaces the flimsy bracket that holds the Y-asix motor on the back right side of the frame that drives the print head front to back. My factory bracket fell apart during a print job. I'm fortunate to have two 3D printers so I design and printed a replacement. The redesigned part is beefier. The holes are in the proper place so it's an easy repair job once you are able to print this model. Of course if all you have is a broken printer, then you can't print this part. Contact me at kent.roller google mail and I'll send you a printed one. Also check out my youtube video for more details and contact info. https://www.youtube.com/watch?v=24W1xOPrz5U DON'T MAKE AND USE THIS IN YOUR PRINTER WITHOUT ADDING A HEATSINK/FAN TO THE STEPPER MOTOR. Stepper motors get very hot and can deform PLA and ABS plastic. I used this bracket after printing it in PLA and it worked fine until heat from the motor warped the bracket.