This item goes along with the Foxy Fan Duct and routes the air under the carriage to direct it at the head location. It mounds on top of the rear belt clamps for the X carriage. I marked this as a work in progress because: This print builds a lot of support material and the hardest part is getting the internal supports out. I had to jam some long nails and tweezers in there for a bit to clean out the duct.