Summary These are plastic parts to hold up the T8 trapezoidal screws centered thanks to a 608ZZ ball bearing. These parts are suitable for version 2.01 of the p3steel frame and others if identical. Make sure of the shape of the metal parts. UPDATE 2017-02-25 Pictures of the realization (orballo variant version for me) UPDATE 2016-11-09 Aesthetic revision (v1.01) of nuts holes (parallel alignments of the nut with the edge of the plastic piece). I made another specific version of the plastic parts for the variant of the z-top frame sold by Orballo Printing in Spain. This z-top is narrower and has some improvements including the holding screw of the Z rod thanks to a lateral screw. Now, you have the choice to take the classic version or "Orballo" variant depending on your Z top. BOM : 2 x 608ZZ 6 x screws CHC M3x16 DIN 912 6 x nut NYLSTOP M3 DIN 985 4 x printed plastic parts (ie left and right version) ** Update : take classic version or "Orballo variant"