These are the ribbonpates. They hold the ribbon in place, you need two of these. To build the microphone you must order the next parts, Part 1 the motorframe, Part 2 the capsule, Part 3 the stelframe and 2 times Part 4 the ribbonplates. These parts ar all 3D printed parts. For making the microphone work you need to a couple of more parts. They are, 2 magnets, 1.8 micron alluminium foil, audiotrafo ( we use the trafo's from BeyerDynamics), a piece of thin copperplate, 1 Neutrik male XLR connector and a couple of 2 and 3 mm nuts and bolds plus some wire. You can look for these parts yourselve our order them at firstname.lastname@example.org. If you need detaild instructions, have a question please send us a email. We are working hard to finisch our website so you can find all the info there.