SINGLE THRESHOLD: includes (1) 80-in long add-on trimmable threshold; threshold has a 4-in wide flat surface to accommodate shower doors TRIMMABLE: trim up to 4-in in width away from either side of drain or up to 2-in in depth away from drain without any loss of integrity MATERIAL: sheet molding compound (SMC) material is made from a composite material composed of resin, fiberglass, and stone filler to create a lightweight and durable material that is stronger than acrylic SINGLE THRESHOLD: the unique adjustable depth threshold is designed so the maximum depth can be adjusted by up to 2-1/2-in without any trimming of the base; 4-in threshold depth accommodates any shower door DRAIN: center drain location with modern rectangular stainless steel drain cover that conceals a conventional 2-in shower drain, creating a pleasing uniform and minimalist design; drain not included