Cloud X 4 AD Trainers Designed for versatility, the Cloud X 4 Ad trainers from ON are dynamic and durable. From daily commutes, to HIIT cardio, the newly engineered mesh upper delivers seamless performance with a lightweight and breathable feel. Featyring an updated heel feet and fork-shaped Speedboard® that increases flexibility, making for a comfortable wear. Light, cool and breathable with a mesh upper Comfort and support with CloudTec cushioning Raised collar edges and a wide base for top stability