ultralight cross trainer Up your functional fitness training routine with the Core™ Containment shoe. An ultralight-engineered mesh chassis is coupled with durable ripstop overlays to enhance gym performance. The Core Containment features a siped rubber outsole for increased smooth surface traction and a hi-rebound foam insole for enhanced comfort during workouts or everyday wear. Designed by US veterans and built for your daily grind, it comes with our one-year Tried & True™ warranty.