This set is ideal for speed development, power and increasing vertical jumps. This training focuses on learning how to move from a muscle extension to a contraction in a rapid or “explosive” manner in specialized repeated jumping. Each element of the set has heavy steel construction with non-slippery top. The set has 5 boxes. Each one has individual sizes and different heights (15 cm, 30 cm, 45 cm, 60 cm and 75 cm). It is possible to stack them all into each other for easy transportation.