The National Marker Company Exit Sign indicates the location of required exits around the facility. The .050" material is a combination of polyester film applied to rigid polystyrene. This material is non-toxic, nonradioactive and glows for more than 6 hours in total darkness. This product exceeds the following standards: ASTM, IMO, ISO/CD, NFPA and OSHA. The sign is standard with radius corners and pre-drilled corner mounting holes.