This is what worries me about some of Dasetn's designs: when he decides to release a DIY mod version of established maker's earbud models. He should not have done a straight mod of the Sennheiser MX760. I love my MX1 and have no doubt that the MX760 sound great, but he should have continued with the generic housing of the MX1 (although that was originally also a Sennheiser design - for the MX400 model). I mean, I don't want Dasetn to be sued by a established company when he's got a real talent for making good sounding earbuds...
He did recable the MX760 to the proper length, but left the "MX760" part on it.
The housing does have "Sennheiser" on it, but he is very clear that this is not the original Sennheiser product.
Technically, you can buy a Ford car, mod it and sell it for higher price - it's not illegal, even if you leave the "Ford" trademark on it.
He is too small to be sued.
Go to taobao and see how many Sennheiser fakes are there.
Even on Amazon.com people complain of getting fake IE80.