These Airport Stencils are made to meet the specifications for FAA airport standards for character markings, used on runways, taxiways, and aprons (Page: B-1 - AC No: 150/5340-1M). The letters and numbers height standard is 12 feet (3.7 m), and may be reduced down to 9 feet (2.75 m) as necessary to fit the marking appropriately. All 1-800-Stencil’s are professional quality and made from either Light or Pro-Grade LDPE, Aluminum, or optional UHMW plastic to all last for years of professional use.