The Iron Man Mark IV neck armor, Part 1 of 2, this is the front half only. if you want a complete neck you will need to order part 2 also. Designed to print at a thickness of .72mm, (minimum for Strong Flexible Plastic is .7mm). This saves on printing costs and WILL need some reinforcement on your end. Most people use fiberglass resin.
WARNING: Not guaranteed to fit everyone. If you have a very short or thick neck, I can't guarantee that this will fit. The circumference of my neck is 37.5 cm, and there's still a bit of room to move around. So I'm guessing that it will also fit someone with a neck circumference of up to a 41cm.