http://gizmodo.com/5979988/a-soft+shell-helmet-that-bounces-back-with-every-hit


The new type of lining, Vinyl Nitrile, is soft and flexible unlike traditional expandable helmet liners. So where most helmets are pretty much done after one hard blow, the Combyn snaps right back into shape, ready to go again. While there's no set number of impacts the helmet can take, the cool part is that the user can send the helmet in to Giro and have it analyzed for its current durability—totally free of charge.