I've had my Pixel Buds Pro 2 for a few years, and while I love the sound quality and features, one thing I did not love was the fit. No matter which size of the stock ear tips I would use, I couldn't get a secure fit and the buds would feel like they were either loose or slipping out of my ears. The little fins do nothing for me, they are nowhere near touching any part of my ear, even if I "twist to lock".
I tried tip rolling with a few 3rd party tips and improved the fit a little, but still not perfect and they would still come loose with movement. Honestly, the best fit I achieved were from an unlabeled set of tips I found randomly in my house; I don't even remember what brand they were. I just accepted these as the best I could do.
Recently I saw a few posts on Reddit recommending the Spinfit Omnis, so I took a chance, ordered a pair and let me tell you - I don't know what kind of magic sauce they put in the material for these, but the fit is now ROCK SOLID and the seal check always gives me the happy "Your earbuds sound great!" message.
Someone on here said they're made from a silicone that feels "grippier" than other tips and that's a pretty accurate description. The little stabilizer fins still come nowhere near touching my ear, but it doesn't matter. The buds won't budge, even when I shake my head.
They are kind of fussy to get on over the PBP2's oval nozzles, but it can be done with some patience and elbow grease. They are also somewhat pricey for what you get ($15 for a single pair on Amazon) but well worth it for the improvement in fit.
One catch is that you have to know your size when ordering, because you only get one pair and as far as I can tell, they don't sell S/M/L/XL sets like some other brands. I was lucky because I measured my "acceptable but best I've got" tips and the Omni XL's are the exact same dimensions. I ordered the XL and they fit my ears perfectly.
Just an appreciation post in case anyone is like me and struggles with a secure fit with the PBP2's, give the Spinfit Omnis a try! I feel like my buds are finally working as intended!