The helmet has a circumference size of 62 cm (average adult head size). The STL files are segmented in 7 different Parts to print easly. 01_HelmetBottom - Bottom part of the helmet 02_HelmetTop - Top part of the helemt 03_HelmetEarLeft - Sides ears of the helmet 03_HelmetEarRight - Sides ears of the helemt 05_HeadCap - Support for more comfortable use 06_Screws_HeadCap - Screw the headcap to the helmet 07_VisorFrame - Visor support. It can be placed or removed comfortably.