Our Glow In The Dark Arrow Signs are made of pressure sensitive vinyl film, washable, non-toxic, non-radioactive and abrasive resistant. In total "black-out" or "brown-out" signs will show the way out of emergency situations. Signs measure 13 x 3 inches and require only minimal exposure to a natural or artificial light to glow over and over again. Apply these presure sensitive signs to any clean, smooth non-porus surface. Glows for several hours and recharges in less than a minute. Conforms to and exceeds sign requirements of OSHA. If you desire temporary mounting, simply fold back corners to expose adhesive and stick in place.