We use the same base helmet for every creation, specifically a Pro Tork R8 Inmetro and DOT certified helmet, which is useable in some countries (but not all so check if you want it for Karting or road use)! 

The helmet is as follows:

Made from high impact injected ABS plastic

2 MM thick visor designed for scratch resistance

Micrometer chin strap - secure and thick

Fixed anti allergic padding

INMETRO certified