Grayne MTN Ski and Snowboard Helmet Grey w/Audio Ready Liner Grayne MTN Ski and Snowboard Helmet Grey w/Audio Ready Liner: Weighing in at just over 14 oz, the MTN is one of the lightest helmets on the market! An adjustable slide lever on the top of the helmet controls 8 individual vents ensuring you are comfortable whether it's 0 degrees or 40! The super warm liner and ear flaps protect you from the elements so you won't even need a hat when wearing the MTN! Oh, and it also comes fully ready for audio inserts. For the perfect fit the MTN also features a twist-to-fit dial on the back of the liner. Finally the MTN finishes with a goggle integration design that routes the strap along both the shell and through a rubber retention strap to lock your goggle strap firmly in place all day long! CPSC and EN 1077 certifications ensuring that the MTN will provide maximum protection! Fit: Twist-to-Fit Dial System Simply twist the dial on the back of the liner to find the perfect combination of comfortable yet snug. The innovative harness design matched with the Twist-To-Fit Dial System allow the MTN to fit an unparalleled size range with the Medium comfortably accommodating head sizes from 54-59 cm and the Large fitting 59-64 cm! Audio Ready Liner The MTN's on the fly adjustable venting can be set up for any conditions with a simple slider on the top of the helmet.