The H570 eartips were what the designer of the Butastur used when tuning the iem and are what he recommends. I wholeheartedly agree as I rolled many tips and these seemed to strike the best balance. You can find plenty of sellers on Aliexpress for these as well. They'll be a clear, hybrid latex tip with a blue center.
Feaulle H570 or Pentaconn Coreir are best for me.
The tips are definitely the H570... No point on messing around IMHO.
Also if you source is more on the analytical side, yeah they may sound thin... The thing is, they are very transparent so everything has more impact in the sound when compared with some other IEMs.
thx ! just ordered the h570 just now.... hope it wont take long to arrived
and yeah, i test it first on fiio k9 pro , after that test it on ru7 for a moment, and i think it sound fuller on ru7 ... but i guess ill wait till i get better to test them again