I purchased this about a year ago for my son's pitching practice, but I'm selling it now because he no longer uses it. It's in excellent condition, as it was hardly used. This is the "Gyro Stick," a gear supervised by Kazushi Tezuka of Joutatsuya, designed to help you master "Ideal Pitching & Throwing." It's designed to make a sound only when the arm passes through the correct swing path, making you aware of pitching and throwing motions that are in line with the human body's mechanics. ● DESCENTE ● Size: Length: 19.5cm, Width: 7.5cm ● Materials ・Body/Polyurethane ・Whistle part/ABS resin ● Color: Black