Made of white virgin Teflon, 0.4 density, 0.003" thick. Over 50% elongation and chemically inert. Provides a strong tight seal for any threaded joint and permits easy disassembly. Tolerates -400 to + 500 degree Fahrenheit. . Suitable for use on oxygen syste ms. Non-toxic and non-flammable. Meets Federal Specification T-27730A.