The Bauer Hockey Helmet IMS 11.0 is the top model of the helmet from the IMS line. This fantastic helmet combines a handful of the protective features and technologies in hockey. The advanced protection is provided by the newly designed Seven Technology ™ and Poron XRD ™ foam. Bauer combines their newly acquired Seven Technology ™, the cluster of 7 cones that efficiently manage high and low impacts, with their state-of-the-art and foam, Poron XRD ™, to provide the highest level of protection for players. The Seven Technology ™ strategically responds differently to high and low impacts and provides the best protection in all situations. The Poron XRD ™ foam is used in the front of the helmet as a high protective memory foam, while also being perforated to promote ventilation. This helmet has a low profile and aggressive look that many professionals prefer. On the back of the helmet, the new Profit2 ™ Adjustment System offers a 15-point secure fit that keeps the protection in its proper position. Working with the tool-less shell adjustment feature, this IMS 11.0 can be adjusted exactly on the fly, no matter what kind of situation a player is. When ordered in white, the air vents are also available in white > size S usually fits with a head circumference of 53.5 - 56.5 cm > size M usually fits with a head circumference of 56 - 59.5 cm > Size L usually fits with a head circumference of - 59.5 - 64 cm