Original E3D blue injection molded fan duct, for attaching a 30mm fan onto the heat sink. This product is required for reliable performance.
If you need to couple a 30mm fan to a 22.3mm cylinder then look no further! The beautiful new E3D v6 fan ducts are injection molded out of translucent blue polycarbonate. They are much harder wearing than printed parts and because they are manufactured to tighter tolerances they are significantly less prone to vibration.
These ducts are not compatible with v5 HotEnds.