Full Grain Leather Shell: For great durability. ButterSoft Palm Liner: PU palm lining for increased durability, feel, and comfort. MZO Lining: Disperses perspiration away from the skin. Polyurethane PowerLock: The simplest and most secure fit available with PU pull tab. HiLo Lacing: Alternating lace pattern retains the integrity of a fully-laced web with greater flexibility.