Vestil Wheel Chair Telescoping Ramps, models D-TR-72 & D-TR-88 are constructed of lightweight aluminum extrusion. Top surface is serrated for positive traction. The Americans with Disabilities Act requires that all buildings must be accessible to disabled persons. Failure to comply may result in monetary damages and civil penalties. According to ADA rules and regulations, for every inch of rise you must have a foot of ramp in length.