Is this a brand new iPhone 6 or a refurb?

I just received an iPhone 6 from Assuiron. It's an insurance replacement company for at&t. We do not need the phone now and I want to sell it. It's in the iPhone packaging and still sealed with plastic. Can I sell this as brand new? I don't want to open it but I don't want to mislead people if this is a refurb. Is this a brand new iPhone 6 or a refurb

According to Assurion they send you a refurbished phone. You can be honest by saying it is mint in box