Rifle Scopes What to look for when buying used?

[nohair]

I'm looking at a used NightForce 5.5-22x50 MLR , mil adj, zero stop, and I am curious what to look for? Anything that is a deal breaker? Roll the dice?
It is suppose to be new , only mounted but I know what that means, I will be able to look before buying.
Thanks for your input,
NoHair