Not every youngster's day on the trail requires World Cup level protection. On days like this, the Troy Lee Designs Speed Knee Sleeve's 4mm D3O protective foam material provides impact protection. The seamless 360-degree construction keeps the pads comfortably in place. D30 Protective Foam InsertD3O provides extremely thin and advanced protection against impact. An expert team of chemists and engineers combine advanced polymer chemistry with cutting-edge design to create soft and flexible materials that don't compromise comfort, but are strong enough to protect in the harshest environments. D3O absorbs and dissipates the energy of impacts, reducing the force transmitted to the body compared to standard foams.