Whether its uphill or downhill - make sure you've got your Hex 15 bike helmet with you. It has a sophisticated ventilation system that channels the airflow to the back of the head, keeping you nice and cool and preventing you from sweating too much when the going gets tough. The Roc Loc 5 adjustment system allows you to adjust the height as well as the width and ensures a secure fit. The visor protects against rain and sun, is easily adjusted and won't rattle when you get going. The in-mold construction keeps the helmet light without compromising durability. You can't go wrong with the Hex 15 bike helmet.