MoMA Exclusive: This cheerful Bioserie rattle attracts babies over three months old with its soft sounds and bright, contrasting colors. The Round Rattle is designed for babies to pass from hand to hand, developing eye-hand coordination and audio perception skills. Shaped like a ring with a rattling jewel at the top and several small balls inside that can be seen as they move through the ring, the Round Rattle’s dishwasher-safe, 100% plant based bioplastic construction makes it a smart, safe, nontoxic option for your little one. 4.1”diameter. For children over three months.