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