The SMITH MAZE AD helmet with a clean, modern to minimalist design is one of the lightest snowboard helmets. It is certified and therefore safe for both snowboarding and downhill skiing. Details: Helmet design using In-MoldTM technology, reducing the weight of the entire helmet. Use the SkullcandyTM Bluetooth® or Twin-Tip Link Phone / Audio to connect the audio system inside the helmet to your phone or mp3 player. (not included) Removable clips holding eyeglasses in place 9 Airflow Climate Control vents - Airflow ventilation allows easy adjustment of ventilation depending on natural conditions. Just pull out the plugs from the ventilation holes and your skull will cool down. In bad weather, you're back. AirEvac 2 ventilation maximizes air through the glasses and helmet. Warm air is removed from the glasses through the helmet through special channels. This reduces eyeglass fogging and allows you to control the temperature inside the helmet. Snapfit Ear Pads - shaped and comfortable "ears". Size chart "adult": size S 51-55 size M 55-59 size 58-60 size 60-62