Question about legal limit of tint

I read that Texas allows 25% VLT. I haven't seen 25% tint, I have seen 80, 70, 30, 15, 5.

Does that mean 30% is ok but anything letting less light through (15 and 5) are illegal.

What VLT are the rear and side privacy glass windows on a typical SUV? or how would I look up the value on a specific make/model?

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