3 in 1 Fitness Music and Lights Piano Mat- 0~6 month Exercise legs coordination, baby’s feet kick the piano and promote the development of the legs. 6~9 month Promote the development of the spine, exercise your baby's crawling ability, promote coordination of hands and feet 9~36 month Grab the toy and hit the piano, exercise hand and feet strength, enhance the coordination of the mind with the hands and feet