STX K18 Arm Guard - Men's With a design inspired by pro attacker Kyle Harrison, the STX K18 Arm Guard is geared for high-impact play. A two-piece, soft mesh sleeve and plastic elbow caps combine to bring protection that is still comfortable to wear. Adjustable top and bottom straps keep the guard fitting properly. Finished with custom K18 details. Sizing: S (for players 71-90 pounds), M (for players 91-140 pounds), L (for players over 140 pounds).