Panel Material: 22 mm Maple/Birch Solid Hardwood Panel Keel Material: LVL elastic dual keel (double protection against moisture and corrosion) Shock Absorption: 57% Vertical deformation: 2.7 mm Ball Rebound: 94% Friction: 95 Water Resistance: 33 mg Rolling load resistance: 0.30 mm Lifespan: 15-20 years