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 helmet02_HelmetTop - Top part of the helemt03_HelmetEarLeft - Sides ears of the helmet03_HelmetEarRight - Sides ears of the helemt05_HeadCap - Support for more comfortable use06_Screws_HeadCap - Screw the headcap to the helmet07_VisorFrame - Visor support. It can be placed or removed comfortably.