6d atr 1 sonic helmetthe atr 1 range of helmets from 6d are the first premium off road helmets designed with state of the art technology to reduce low threshold impact energy transfer and angular acceleration to the brain during impact ultimate protectionthis lightweight atr 1 sonic helmet incorporates the superior benefits of 6ds ground breaking omni directional suspension tech and has no equal it has also been developed with multi density eps materials and isolation dampers to provide ultima