What does the head's abrasive material consist of?

The abrasive head consists of a layer of ultra-pure Carbex mineral crystals.
Carbex is silicon carbon, a bio-compatible, anti-allergenic material.
A sample group of this product has undergone in-depth tests and experiments, with the following result:
- the product is non-irritant and non-sensitising (non allergenic);

Test manager: Dr Erika C. Schmitt, medical     surgeon and  dermatology specialist.
Certification: Authority certification Ager test No. A462/06 exclusively licensed to General Project Srl.