Kerdi-Kereck-F are preformed, seamless corners for waterproofing the corners of Kerdi and Ditra assemblies to prevent leaks. The 4 mil thickness helps minimize build-up in the corners. The KERECK/FI2 is a package of 2 inside corners. Package contains 2 inside corners Preformed, seamless corners made of Kerdi Thickness is 4 mil Ensures a fully water-tight seal at inside corners For use with Kerdi and Ditra installations Convenient and easy to install