The Storm GTX is 70% carbon/ 30% glass for a nice mix of lightweight and durability. Features -Quick-release magnetic straps for convenience and good ergonomics. -Improved durability has over the initial design from four years ago. -Strap system works well with overstrap mittens. -Changing baskets and roller ferrules is easy with One Way’s twist lock system. Mix and match striking colors to stand out in the crowd! Sizing: -Large strap for hand size 9 and up or smaller hands with heavier mittens.