This is general product-selection guidance, not engineering advice. Confirm the final product and specification for the application.
Describe the contact environment
List oils, fuels, water, weather, food contact or chemicals the material may encounter.
Provide dimensions
Supply thickness, width, length and the finished gasket or seal dimensions where fabrication is required.
Temperature matters
State the normal and maximum operating temperature rather than selecting by appearance alone.
Confirm the specification
Where a standard, grade or approval is required, provide the exact requirement for confirmation.