STX Stallion HD Arm Pad - Men's The Stallion HD Arm Pad is how to get top-of-the-line STX performance when you step on the field. It's constructed with dual-density High Def™ Polymer and a new fit system. Together, they bring an improved anatomical fit within the full-length, breathable sleeve. Lycra® was added along the forearm for more stability. Even more, this pad also contains odor-defense technologies. Sizing: M (for players 91-140 pounds), L (for players over 140 pounds).