For Large Format Floor Tiles between 3/16 and 7/16 inches thick. Should only be used with a minimum 1/4 x 3/8 x 1/4 inch square trowel notch to apply the setting material. For optimum results, a 1/2 inch square notch is recommended. For use with porcelain, ceramic, and all natural stone tiles. Also great for use with tiles of varied thickness. Prevents tiles from moving during the entire installation. Wedges are reusable. Clips must be purchased separately.