The signature STX trestle sidewall provides extra stiffness and durability making the 10% stiffer than the Xcalibur. __Additional stringing holes for easier stringing. The sidewall is the key on this defensive head, as STX specifically designed it for maximum stiffness, but to deliver smashing pokes and slap checks. The X-10 shines in all aspects, from its customizable pocket, stringing holes and its rugged durability. Defensemen who have purchased this head have raved about it, calling it the “ultimate” defensive head on the market, and we are inclined to agree. One of the best we have to offer, you will see this head on the top of every D-pole shaft on the elite collegiate level.