Schluter Kerdi-Kereck-F Pre-Formed Inside Corner (1 Ea) Stock KERECKF1 is designed to provide seamless waterproofing for inside corners in tile applications. Made from durable orange polyethylene, these pre-formed corners are specifically crafted to work with the Schluter Kerdi Shower system, ensuring that the inside corners of showers remain waterproof and ready for tile installation. Suitable for both commercial and residential use, the Kerdi-Kereck-F corners are easy to install using unmodified thinset mortar and a 1/4 in. x 3/16 in. v-notch trowel. Their thin, 1 mil thickness prevents any buildup beneath the tile, making them an efficient and reliable solution for waterproofing shower corners. Model Number: KERECKF1