The Empervious ramp is made of 100% waterproof XPS Foam core, reinforced with fiberglass mesh and finished with a cement coating for added durability. The low profile shower ramp allows for barrier free shower pan installation if you are unable to or do not want to lower the subfloor. This is a perfect solution for concrete subfloors. The ramp is 1” high and slopes down to a ¼”, leading into your ¼” foam or backerboard on the floor. The 1” height aligns perfectly with all of the center drain Empervious Low Profile Shower Pans, except for greater than 84”. For offset drain and pans over 84” that measure 1-1/4” in height, the ramp would need to be shimmed with a ¼” foam board to match the height.