This is the sloping part of the Ghostbuster's proton pack booster from Steffan Ottos' plans at: http://www.gbfans.com/wiki/Stefan_Otto%27s_Prop_Plans Use in conjunction with: http://www.thingiverse.com/thing:518252 The axis for the tube is printed orthogonally to the print plain. This is because the two cylinders on the top of the part cannot be printed it positioned any other way. Some post print cleaning will be required.