The new Tacks 310 helmet was designed to offer state of the art comfort and fit. With its completely new comfort liner, it delivers an amazing fit and incorporates D30 Lite  to offer a high level of protection. Scientists indicate that brain injuries and concussions are mainly due to linear and rotational accelerations of the brain. No hockey helmet can prevent or eliminate the risk of head injury, including concussions. LINER New I.Q.shion foam comfort liner with D30 Lite. High level of protection and offers a premium level of comfort and fit. ADJUSTMEN Easy adjustment at the back of the helmet for a wrap fit and high level of comfort. SHELL Designed to maximize protective capabilities. A pro preferred look with geometry that helps absorb impacts. Small      20\" - 22\" / 21 - 56cm Medium  21.5\" - 23\" / 55 - 59cm Large      22.5\" - 24.5\" / 57 - 62cm