Easy set up rust-resistant metal frames heavy-duty PVC and polyester 3-ply side walls built-in flow control drain valve makes it easy to drain by attaching the valve to a garden hose (with included adapter) to drain away water. Underwater adhesive repair patch shelf box with picture extra strong sidewalls are made with 3 separate layers of material. The inner layer of polyester mesh is laminated to the 2 outer heavy gauge PVC layers. This creates a total thickness of 0.40-0.80mm (16-32 gauge) depending on the size of the pool.