I wrote to 1Z a few months back and this is what they told me:
"
Hello Jorge,
Thank you for your email. Cockpit Premium lacks the strong UV protection of
exterior protectant Vinyl-Rubber Care 'Tiefenpfleger' due to its intent to be used on interior surfaces. Today's automotive glass already filter the majority
of UV rays. Therefore, additional UV protection is unnecessary. The only time this is not the case is if you have a convertible top in which case a protectant like Vinyl-Rubber Care will offer protection. What Cockpit Premium does contain are ingredients that protect against fading due to heat. You can spray Vinyl-Rubber Care on interior surfaces as well but you should not apply it on areas such as the steering wheel, pedals and shift knob due to its slippery finish.
Hope this helps. If you have further questions, please do not hesitate to ask.
Thank you again and best regards,
Mike
einszett Customer Support
Orange, California 92867
888-719-4698
"
So I guess it doesn't have much UV protection but according to them you don't really need it :nixweiss: .