Hi, 

Today i'm going to buy used Marshall Major 3 Bluetooth Headphones and since i'm buying used ones  and not from official store or official retailers, I want to know is there a way to check serial number of the product to be sure if it's fake or origianl headphones?.

also if you can provide guidelines how to differentiate Genuine Marshall Major 3 Bluetooth from Fake ones that would be great.

Thank you beforehand