A piece of Schluter®-KERDI-BAND can be cut to 3-3/16" x 4-3/4"-6" (88 x 120-150 mm) and substituted. Use a Schluter® thin-set mortar or Schluter®-KERDI-FIX to hold in place. The self-adhesive patch is used for proper thin-set mortar adhesion and preventing mortar from entering the connection box. It is not intended for waterproofing.