This is a fully enclosed one piece infant seat that prevents small children from falling out. It is made with a steel insert that is encased in 70duro EPDM rubber with heavy duty rust resistant triangular hardware. EPDM: Ethylene-propylene-diene-monomer which is a synthetic rubber material which helps prevent crazing, cracking and oxidizing. This seat has a 36" circumference, 11" diameter, 12" deep, with a 5" leg opening. The seat should last 2 years in harsh conditions and up to 5 years in optimal conditions. Some conditions may require replacement sooner.