Got Spinfit CP100Z for my KZ-ZS5s a while back for $8.99 on Amazon. The isolation level got kicked wayy up. I gotta say I honestly did not expect them to make such a huge difference. Just found out that they're having a father's day deal too. $5.99 each on the two models that they claim to pair extremely well with most of the true wireless earphones available on the market. So they came out with CP100Z and then the CP350, both claiming to be the best replacement eartip for true wireless earphones. Wasn't sure how to choose for my true wireless earbuds, but then they posted this comparison graph on their facebook and I thought it could be useful for people who wants an affordable easy upgrade for their true wireless earbuds. source: https://spinfiteartip.com/news-detail/8 Oh and I've said this in another thread before, but I'll just say it again........ I was pretty confused as to where to find Spinfit tips because there were a lot of websites and emails floating around. Then I finally got in contact with Spinfit........asked them where I could get authentic Spinfit and reach them most effectively. So here you go: Facebook: SpinFit Eartip Official Amazon Store: www.amazon.com/shops/Spinfit-Eartip New Website: www.spinfiteartip.com Bought my CP800 wayyy back. I think Spinfit works especially great for over ear positioning & those who have improper fit for typical stock silicon tips (totally helped me wear IEMs with unusual fits that I otherwise have trouble wearing). One reminder though, they don't actually spin, they are just able to flex in any direction. But honestly, it didn't matter to me if they actually "SPIN" or not. ‘Cause for me, Spinfit resulted in the greatest fit and a sound quality I've simply never experienced with any other buds before. And I think Spinfit has really stepped up their game.... From not being able to find their sites and contact info, to having a pretty awesome new website & got giveaways going on their facebook and stuffs. Can't believe that they don't have much followers yet o_O (at least it seems). Anyways, gonna take advantage on this father's day deal and give CP350 a try ....... Thought I would do a poll and see how many of you out there are into these magical tips like I am.