This is a 3.5" drive to 2x 2.5" drive bay adapter. Printed in PLA, with 20% infill, weighs only 36 grams. This model can accommodate both 7mm and 9mm drives (7mm pictured). The mounting screws and hex nuts are standard M3, but any screw should be fine as long as the mounting hex nut has an outer diameter of 6mm or slightly less. While the mounting screw and nut are M3, it is important to note that 2.5" drives utilize M2.5 screws for mounting. The screws and nuts I used were "https://www.amazon.com/gp/prod..." and "https://www.amazon.com/gp/prod..." respectively. Anything with similar dimensions would work just as well. I am in no way trying to promote or advertise these products, but they are the only ones I can guarantee work.