Sliding Door Enclosure Corner Entry Doors Quadrant Enclosure Diamond Enclosure Walk in Enclosure Bi-Fold Enclosure Pivot Enclosure Shower Accessories Towel Rail. Quadrant Rectangle Square. 【 Durable construction】 Our trays are constructed from a polyurethane resin mixed with filler, including volcanic ash, making them more durable and long-lasting than traditional shower enclosure trays.