Alternative to traditional wood keel blocks.Long lasting alternate to traditional wood keel blocks. Each tube is 8”x8”x20” (20x20x51cm) and weighs only 33 pounds 15kgs. They have been load tested to 40,000 pounds (18 tons). If your wood blocks are splitting or rotting this may be an alternative. The tubular construction is easy to grip and carry.Key FeaturesTubular construction is easy to grip and carryWeighs only 33lb.Customizable stackingUse two blocking piles placed on hard, stable ground to carry the boat's weight