Irrespective of brand, the vast majority of cycle helmets available are made from polystyrene. They do work, but are fragile and can break after even the smallest of knocks.
Headkayse have tested their prototype by subjecting it to 100 full impacts on a drop rig to the same spot. Hit 101 has been conducted at Inspec International on an official test rig and the result is STILL a pass.
We think a cycle helmet should be as tough as the life it has.