Thank you for viewing. I bought these hoping my child would learn the correct form and run faster, but the Dash Driver Zeku was only swung around once indoors to make sounds and then put away. The Dash Beat was only taken out of the box, but not out of the bag, so it's unused. I have checked the operation before listing. ◆MIZUNO Dash Driver Zeku ~Excerpt from the official HP~ To run fast, in addition to leg strength and foot rotation, forward propulsion through correct arm swinging is necessary. Swinging your arms forward and backward widely so that the angle of your elbow is 90 degrees is the ideal arm swing that Mizuno proposes. "Dash Driver Zeku" was jointly developed with the toy manufacturer Takara Tomy Arts Co., Ltd., and is an item that allows children to learn the arm swing form for running while having fun, and to master the correct way of running. It looks like a hero's item, and by simply wearing it like a wristwatch and running, it notifies you of the quality of your running with sound, and it has a function that changes the sound when your arm swing becomes faster. ◆MIZUNO Kids Dash Beat ~Excerpt from the official HP~ You can learn the technique of "drawing your feet forward compactly" which is necessary to run fast. Please purchase if you can accept home storage. If you have any questions, please comment. ꙳★*゜Please read the profile before purchasing, if you don't mind꙳★*゜