Fluorozone? Mil-Spec Performance FKM sheet is formulated to meet the AMS 3216 specification (supercedes MIL-R-83248) and is made with 100% virgin domestic-made premium Fluoroelastomer polymer. Fluorozone Mil-Spec Performance FKM is our second offering in the Fluorozone? FKM product family. This material exhibits a higher temperature range (up to 500°F) and increased tensile strength compared to Fluorozone Premium Performance grade. Fluorozone has very good resistance to many aliphatic hydrocarbon fluids that can dissolve many other types of rubber and has resistance to a broad range of oils, fuels, lubricants and most mineral acids.