It’s important to keep in mind that your KERDI-LINE-VARIO channel needs to be placed such that the opening in the center of the channel is directly above the KERDI-LINE-VARIO flange connected to the drainage outlet. Measure from the center of the outlet to where the channel will end on both sides. The 4-foot channel provides you with a maximum of 2 feet on each side of the outlet, and the 8-foot channel gives you 4 feet on each side. Each side of the channel and grate can be cut to size to fit your shower, keeping in mind these maximum values. So for example, if your drain will span 4 feet, but your outlet is positioned off-center at 1.5 feet from one end, you would need an 8-foot channel and grate assembly and cut 2.5 feet from the side closest to the drain, and 1.5 feet from the other.