What Is 3M FX-ST 5?

3M FX-ST 5 is the darkest shade in the FX-ST automotive window-film range covered by 3M reference data. It should be selected by its measured glazing performance and visibility implications rather than by generic “legal” or price claims.

Published Reference Performance

In 3M reference data for FX-ST installed on Auto 75 automotive glass, FX-ST 5 is listed at approximately 4% VLT, 61% TSER, 99% UV block and 95% glare reduction. These values are for the stated glass and test configuration and should not be treated as universal installed results.

What the Dark VLT Means

A very low VLT produces a dark appearance and substantially reduces visible light through the filmed glazing. That can increase privacy, but visibility requirements and glass position become especially important. Factory glass changes the final installed result.

TSER vs Darkness

TSER measures total solar energy rejected by the tested filmed glass. Darkness alone is not a substitute for TSER, so compare the exact shade’s solar data rather than assuming that the darkest option is automatically the correct heat-control choice.

Current Vehicle Requirements

Do not label FX-ST 5 automatically legal or illegal from its product name alone. Current requirements vary by jurisdiction, vehicle category and glass position, and the combined factory-glass-plus-film result matters. Confirm requirements before installation.

Compare FX-ST Shades

For lighter alternatives, compare FX-ST 20, FX-ST 35 and FX-ST 50. Use the FX-ST service page or automotive film hub for installation-focused comparison.