X-treme File Bands are nonlatex rubber bands made from an EPDM (Ethylene Propylene Diene Monomer) formula. This type of rubber gives the bands outstanding properties that make it resilient to ultraviolet, heat, ozone, weather and age. Each 7" x 1/8" band has built-in longevity and offers a wide range of applications for home, office and recreational use such as active and archival filing. They are the best solution for those who are required to keep documents on hand for an extended period of time.