This is a mount for the J Tech Laser which clips on the Powerspec 3D Pro (Flashforge/Makerbot Replicator 2X). It's designed to be a tight fit, so it may require some slight sanding to make a perfect fit on the front of the printer's carriage. This position places the laser's lens at an optimal distance for focusing to the smallest possible spot (about 1.2 inches).
Holes are slightly undersized to allow M3 screws to self tap or you may drill them larger to use nuts. 40mm fan blows downward to cool the laser and blow smoke away. It's angled to avoid interfering with the printer's case.