Along with certifications, numerous materials make up the horde of helmets on the market. Thermoplastic is the most inexpensive, but construction needs to be thick because the material is the weakest of the bunch, resulting in a heavy helmet. Fiberglass is lighter, stronger, and costs more, but they’re susceptible to cracking on impact. Composite helmets mix fiberglass with Kevlar and result in a highly durable shell without the fracturing qualities of fiberglass or the weight penalties of thermoplastics. Of course, carbon fiber helmets occupy the highest echelon of market, as production is labor-intensive and the construction is of the highest quality and strength.