If you are going to print the Size A, you need to understand which extended design parts are available to print...
The size A evolved as I worked the design, there are additional parts available that are either exclusive to the size A or have otherwise been combined into the base model for the size B and C
Perforated Visor for Halo Helmet - want to be able to see through a printed visor?
Halo 4 Helmet Full Size A with tiewraps - take control of that wiring harness, with built in tie wrap "warts" in the inside of the model.
Want a PETG vac formed clear visor ready for painting in your favorite metallic?