There are many earphones that may carry the same housing and might look similar inside, but might not sound nothing like each other. SENDIY clarifies that the inner-workings are coming from a well known Taiwanese manufacturering company and they are working hand in hand to put these together. Where, in the other hand, the K1's by MaGaosi are solely made and built in China. And, with that said, lately the K1's have been having issues with either construction or the drivers. Lately, SENDIY's has had a good amount of followers here in China with a Japanese writer reviewing the M1221 with 5 star results as well at China's version of head-fi, "headphoneclub.com". I believe, SENDIY is a more serious player satisfying customers when compared to many other Chinese start-up companies.
Ps. don't know if you remember the SENDIY M2, when another seller tried to copy his M2's with no avail and no competition for that matter. Another note.....the SENDIY M2's came out on a popular TV game show as a promotion here in China. I think that says a lot about a person persueing his dreams and doing things right for his customer base audience and buyers.