Refered to as shell, hard shell, or bombshell construction, this type of helmet features an injection-molded ABS shell exterior with an impact-absorbing foam liner similar to an In-Mold helmet. However in this case, the foam liner is not fused to the shell, but is instead simply laminated to it. ABS plastics are known for being extremely tough and durable while providing extreme impact resistance. These helmets are usually fairly basic in design and ventilation, as the shell material does not allow for additional venting, but are some of the toughest on the market.