Multi-Impact Shell: Combined with an EVA foam liner and a polyurethane sub-shell to effectively dissipate impacts Interconnect Retention System: Securely holds the helmet in place under hydraulic forces, as the force of the water pushes the helmet back, the interconnect system self-adjusts to hold the helmet firmly in place Adjustable O-Brace Harness: Conforms to the back of the head to help keep the helmet safely positioned