The Jensen Vandal Proof Swing Seat uses a tough synthetic rubber that is resistant to many forms of damage including cracking. This design also makes the Jensen Vandal Proof Swing Seat weather resistant and provides for a comfortable but rugged and tough performance. Sporting a tensile strength of 3600 lbs., this swing seat will last for years. Since the seat is made from EPDM (Ethylene-propylene-diene-monomer), it holds up better than all rubber options.