This is what Audio Texhnica said..
Thank you for your email. We can confirm that DV247.com are a very well known and reputable reseller – they have been supplier of our products for many years, and have been known to offer very good service and after-service.
If the impedance is stated as 68ohms, this will be a misprint – I have had a quick look on their website, but haven’t yet found it (can see the PRO700MK2ANV, but this is showing the correct impedance. If you could direct us to the direct page, we will get in touch with their marketing department to ensure it is corrected.
As long as the part number is exactly as you have written, however, so either ATH-PRO700MK2, or ATH-PRO700MK2ANV, then we can guarantee that they will be correct to the specs that we have published on our website. If you were to purchase them, and there was any discrepancy, then you would be welcome to contact us again, however as DV247 are a supplier of ours, we would consider it highly unlikely for them to provide any of our headphones that are modified/not genuine.
We do thank you for contacting us, however, as we would prefer our customers are cautious if they see anything that appears suspicious, to ensure that they buy a genuine copy from an authorised reseller.