The superior quality top seat, made of synthetic resin, features uniform calibration, UV treatment against discoloration and a molecular memory to prevent warping. In addition, the top seat is totally resistant to corrosion and scratches. Unique to Trevi, the double pool support post and stay assemblies are designed for superior strength as well as aesthetics (on the straight side of oval pool only). The bottom safety track, made of galvanized steel, guarantees the stability of your pool.