Summary You can use for key chain and bottle opener! logo of the famous brand of Spezialized bicycles! I created this for my friend who works in the Specialized! him very happy !! Is only 1 washer M6 12x1.6 fit in with force; no need glue or else! Look after your printer calibrated; In the case where the washer does not enter; heated washer and try again. I printed this with Colorfabb Copperfill; and it is very nice! It weighs much more. Print Settings Printer Brand: RepRap Printer: Prusa i3 Rafts: No Supports: No Resolution: 180 - 220 micron Infill: 25 % Notes: Print in PLA; 2 or 3 Perimeters 25% infill