Fully enclosed infant one-piece seat features a high back to offer extra support for smaller children. Made of 70 duro EPDM rubber with an insert and heavy-duty rust resistant welded triangular hardware. Ethylene propylene diene monomer (EPDM) is a long lasting synthetic rubber material which helps prevent crazing, cracking and oxidizing. This swing has a smaller leg opening, ASTM F2373, for children 6 to 23 months. Leg holes are 4-1/4" diameter. Made in the USA. Please specify color when ordering.