Staff Recommendation - We just love S1 Helmets. Not only are they super stylish, safe and an extremely comfortable fit they have the added bonus of being able to be adapted to any size. The shell of all the S1 helmets are the same size, its the inner liner that varies in thickness (with the exception of Mini Lifer and Mega Lifer). So even though they are great for roller derby players, aggressive & recreational skaters plus bike riders they are also great for children with growing heads. It costs under $10 to replace a liner with the next size up, making the S1 great value for money.