The trays are made of lightweight, expanded polystyrene (PS40) for constructing mortar-free shower bases. Each of these sloped, prefabricated shower trays are designed to integrate with the SchluterÂ-KERDI-DRAIN and are available with center drain placement in 38" x 60" (97 x 152 cm), 48" x 72" (122 x 183 cm), and 72" x 72" (183 x 183 cm) sizes. The KERDI-SHOWER-TS with an off-center drain placement is available in 38" x 60" (97 x 152 cm), for bathtub replacements. KERDI-SHOWER-TT features a thin perimeter height that simplifies curbless shower construction and is available in 36" x 36" (91 x 91 cm), 38" x 38" (97 x 97 cm) and 48" x 48" (122 x 122 cm) sizes. Warning: This product can expose you to chemicals which is [are] known to the State of California to cause cancer and birth defects or other reproductive harm.