This is a 7.125 inch shift knob originally made for a 2001 Volkswagen Jetta VR6. The smaller cylinder attaches to the shaft of the shifter and is screwed onto the metal shaft. The boot cover then goes in between the attachment and the shifter handle. The handle threads into the attachment and is knurled so grip. This is just a 3 D rendering made for reference and printing but I would not recommend using it, I plan on making a full aluminium set using this diagram.