RoostrC0gburnI purchased a pair of IE 80 IEMs from Massdrop a few years back and had problems with the cable within the supposed 2 year Sennheiser warranty (they are apparently known to have cable problems) and ended up having to purchase a new one myself for $41.40 after shipping since Sennheiser did not acknowledge Massdrop as an authorized re-seller. This pretty much invalidated any savings I thought I got from purchasing them from Massdrop.
So in my eyes you are purchasing these Sennheiser IE80 IEMs with no warranty.
RoostrC0gburnit is my understanding that even if a product typically has, for instance, a two year warranty, items bought through MD have a max 1 year warranty. i believe this is part of the MD contract with the seller and you shouldn't have an issue with warranty claim within 1 year. However, you may have to find a customer service rep familiar with their MD agreement, or work with MD to find an appropriate contact.