HYDRO BAN Pre-Sloped Extension is made from high-density expanded polystyrene with a liquid waterproof membrane finish coat. HYDRO BAN Pre-Sloped Extension is a lightweight ready-to-tile extension to be installed with the HYDRO BAN Pre-Sloped Shower Pan to extend the length of the HYDRO BAN Pre-Sloped Shower Pan up to 2' (61 cm).