These hinges are for 3mm Acrylic Doors (ex: http://www.thingiverse.com/thing:991861) to flush fit on the Makerbot Replicator 2 / 2X and similar clones with the metal frames and 5mm plastic side panels. These hinges attach to the Acrylic doors with 10mm Flathead M3 machine screws, and attach to the plastic panels with 12mm M3 machine screws. You should also use the stress relieving printed plastic hex washers (http://www.thingiverse.com/thing:755320) when attaching these hinges. These hinges, along with the associate latch are part of an enclosure kit which includes the snap together (as in no fasteners top) for these style printers. The enclosure improves printing by maintaining a more consistent print environment, reducing warping and delamination. The kit is available at: http://drazzticaction.com/products-page-2/3dprinters/enclosure-for-makerbot-replicator-2-2x-3d-printers-and-similar-clones/ Enjoy better printsPrint out hinges, join with a piece of 1.75mm filament for hinge pin, attach with M3 machine screws and nuts.