This bracket is the backbone of the Trestle printer. 6 of them are required for each printer and it will make the frame so strong that you will never have to worry when transporting or when accidents happen. It is made out of 1/8 inch laser cut aluminum. The holes are drilled 20mm apart to be used on the MakerSlide extruded aluminum. The spacing allows the sliders to travel inside the bracket to maximize travel and print size.