Aside of ZST Pro we also received the new ED9 from KZ for a good test! As a cheaper alternative ED9 can be a good choice for those who really care for music quality and versitality. The unique feature of ED9 is that you are able to change the nozzles which can help tune your earphones for your like. Inside the package you can find aside of the standard earbuds the screwable tuning nozzles. As default, we found that the bass nozzles were set which fits more for ROCK, R&B, and Hip-Hop style genres, and the balanced nozzles can be found in a small pouch in the box, which is more preferable for POP, VOCALS, CLASSICAL and other light music genres.