Under Armour Men's Ua Speedform(tm) Xc Synthetic-and-mesh Innovative UA Speedform Technology - Delivers zero distraction while running. Seamless Heel Cup with Silicone Grip - For a locked-in, anatomical fit. Perforated upper with ultrasonic seal for durable breathability. Smooth, Ultrasonic Welded Seaming - With Bemis tape for next-to-skin support and comfort. Molded 4D Foam Footbed - Conforms to your foot's exact shape, eliminating slippage.