Handmade replacement toy balls perfectly fit mamaRoo swing mobile and have different sounds. One ball has crinkle sound, second ball has a rattle sound, and the third ball has a red stripe that attracts the eyes of the newborn. Toy balls could be used during tummy time. Handmade from 100% cotton. Balls are stuffed with hypo-allergenic polyester fibers. Machine wash on gentle with warm water. Air dry or tumble dry on air or low heat setting. Set included 3 toy balls. Balls fit MamaRoo model 4,1026,1037,1046 and new 2022 model