Petzl have two professional tree worker helmets - the Vertex Vent and the Vertex Best . The cooling effect of the ventilation holes in the Vent make this one very popular (particularly in summer) but Petzl clearly state this helmet does no provide protection from electrical hazards.Consequently some of the bigger arborist companies (doing utility work) are buying the Best as standard issue to ensure workers do not use the incorrect helmet on the job. The lack of protection from electrical hazards is only relevant if you are doing utility type work.
Most customers tell Treetools they prefer the Vent because it is just that much cooler and more comfortable to wear for all day use. Both helmets reach the EN 397 and EN 12492 standards for wear, impact, low temperature and lateral deformation. The Vertex Vent does not meet the optional EN397 standard regarding electrical insulation and molten splash due the ventilation holes.