Fun toy with 3 light propellers that fly high in the air because of geared speed amplification of 21:12, yu can print it in petg, pla, abs or asa, with layer height 0.2. You will ned 3 screws 2.5x13mm, or you can use parts of filament and melt it, you also need to use part of filament on gear rack to handle connection. a little bit of support is only needed on big gear, which is easily removable. If you have silicon oil spray on hand, you can spray a little bit in main body where gears slide.