from senn's website :
How to spot a fake
Unfortunately there is no hard and fast rule. The skills of the fakers can often make it hard to visually distinguish a counterfeit from the real thing. But here are some tips:
If you are tempted to purchase from an on-line auction site, try to establish where the product is shipping from. Genuine Sennheiser products are not shipped from China!
If you are buying a £1000 watch for £20, you know from the outset that it is a fake. However, that rule does not apply when you pay £20 for a £30 headphone. Quite understandably, you think you are getting a bargain!
Remember that if you are buying a Sennheiser product advertised as ‘NEW’, you can only be sure to get an original product if you purchase it from one of our authorised dealers. And Sennheiser NEVER sells products on auction sites. If in doubt, visit our website and click on our dealer locator.
If however you are buying second-hand, you should do everything you can to ensure that you are dealing with a bona fide seller. Caveat emptor (Buyer beware!).
Look for poorly printed labels and material; most fakes have slight differences from the real deal. Compare the suspected fake with the corresponding picture on our web site.
If it proves to be a fake, then we’re afraid that there is not much we can do for you except recommend that you get in touch with Trading Standards Association (
www.tradingstandards.gov.uk).
If the product you have purchased is counterfeit, you are entitled to contact the person or the retailer who sold it to you and demand a refund.