In reply to davy_boy:
I think it's just a precaution as the TLT Radical DIN only goes up to 10. I'm 6' 1" 85(ish)KG and my DIN setting (set by a ski tec) is 8 but i usually crank it up to 10 if skiing hard off-piste with a pack.
There are a few DIN calculators online which are ok at a pinch (they go by height, weight, boot sole length and skier ability, usually) but if in doubt, take it to a ski shop and ask them.