The Protos arborist helmet from Pfanner is the most advanced helmet system available on the market offering the best energy absorption, lightest weight, and unprecedented breath-ability. The side impact protection sets it apart from its competitors and makes it arguably the safest climbing helmet ever brought to market. Choose your color preference from the list below. To conform to ANSI standards, Protos helmets are now made with a grey foam insert, NOT the green koroyd included with earlier versions of the helmet.