White Vinyl Channel Premiere 4 - 4' Length Perimeter channel in 4' lengths.4" Depth.Made of non-corrosive PVC material that will not rust or rot.Perimeter channel should only be used in projects which are framed on 4 sides.Used to anchor smaller glass block projects to the floor or curb; walls and header when another anchoring method is not used.Individual glass blocks are positioned into the U channel after it has been secured to the project’s perimeter.Hose the outside and wipe the inside lightly with a damp cloth.Provides a safe and secure window enhancing your home security.