40″, white, shelf hang track, mounts horizontally level at top of wall & is used for easy installation of the shelf track program, various size standards can hang from the track eliminating the need to screw the standards into the wall, top front facing locks standards in place on track, standards can not be pushed up & out of place, standards must be tilted out to remove, also available in 80″ length, #2836, can be easily trimmed using a hacksaw.