very light helmet with clear design and shock-absorbing inner lining . the sinner whistler helmet offers solid cushioning and maximum protection due to its in-mold construction and shock-absorbing lining. it also has a quick release fastener, goggle holder and a practical size adjustment system. the adjustable shell ventilation allows you to adjust the ventilation individually.constructionwith in-mold ski helmets, the polystyrene foam inside the helmet is glued directly onto the protective thin outer shell. this makes it light and comfortable to wear.ventilationthe helmet ventilation is adjustable, you can simply open or close it to regulate the airflow.fit systemthe fit of the helmet can be adjusted by a wheel.