This upgrade makes the K8200 / 3Drag a dual extrusion printer. It consists of a E3D Chimera / Cyclops mount including the integration of a 40x40 fan. The distance bolts lets the air flow around the heat sink. This mount is independent of any extruder mounting design. In my case I use two BulldogXL extruders. The corresponding mounts are included here. For mounting a BulldogXL please look at https://www.youtube.com/watch?v=qg05LnyRInQ The black gear box covers have dot be replaced by the BulldogXL mounts. The BulldogXL mounts each have 3 mounting holes and it is up to you to fix them with one or two screws each, depending on how many screws/square nuts you have. For connecting the PTFE tubes you need E3D bowden adaptors. Material needed: for Chimera / Cyclops mount: E3D Chimera / Cyclops http://e3d-online.com/Multi-Extrusion PTFE Tube material (included) 2 Bolts M5 x 16 2 Washers 2 Square Nuts M5 3 Hex Distance Bolts M3 x 15 (one end male, one end female) 3 Bolts M3 x 16 Fixing screws for the fan for Bulldog XL mounts: 2 BulldogXL extruders 2 Bowden Adaptors from E3D http://e3d-online.com/Mechanical/Bowden/Bowden-Adaptor-1.75mm-Filament 2 (4) Bolts M5 x 16 2 (4) Square Nuts M5 The E3D Chimera / Cyclops mount as well as the BulldogXL mounts are printed in ABS / 0.2 mm layer height with support, which is easy to remove. The slicing is done with Simplify3D software. The print positions can be seen in the yellow colored pictures.