Increase explosive vertical jump power and speed with Champion Sports Set of Five Plyo Boxes. Used in a variety of plyometric drills and speed training. The plyo box acts as a stable landing surface thanks to the slip-resistant rubber-coated pad. Made of welded steel and constructed at a six-degree angle to prevent tipping. This set of five sturdy plyo boxes are a perfect way to improve your jumping skill and speed. Length: 13"; 15"; 18"; 21"; 24"; Material(s): Plywood; Rubber; Steel; Playground/Gymnasium Sets Type: Plyo Box Sets; Quantity: 5/Set.