Fitness classic in a full range of sizes! Plyometric boxes from Power Systems are designed to provide maximum stability and durability during your workout. Our plyo boxes are constructed of fully welded steel frames, and the tops are made from reinforced 3/4" plywood with a non-slip surface to maximize safety. Black/black. Specific dimensions below. Starter and Advanced kits available. 5-year limited warranty. Use indoor/outdoor. Rubber bottom to protect floors and prevent movement. Non-slip surface to maximize safety. Stackable for easy storage. 6 sizes, sold as sets or individually. Advanced Set: 12", 18", 24", 30", 36", 42".