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 Schluter®-Thinset or Schluter®-KERDI-FIX to hold in place. The self-adhesive KERDI patch is used for proper thin-set mortar adhesion and to prevent mortar from entering the connection box. It is not intended for waterproofing.