Stone Resin BathtubMade in one piece, with a special space inside for connecting overflow and drain.Made in one piece, overflow and drain are integrated inside the bathtub.Highly repairable and long-lasting durability of a stone resin bathtub.Glue the drain to the overflow and bottom drain.The bottom and interior of the acrylic bathtub are hollow and have 4 brackets.Acrylic bathtubs scratch easily and have limited repairability.