Your friends could 3D print and wear the Darth Vader and Kylo Ren masks. You can download its STL files along with the masks of Immortan Joe, black widow halloween costume Darth Vader and other characters. There are two Daft Punk helmet 3D models you can 3D print. Who loves the mysterious ghost Beetlejuice can 3D print an impressive Halloween décor. You can use this simple 3D printing object with interchangeable parts (which you have to design and print yourself or find as avengers costume ready-to-buy accessories).
