You might have to shorten them to get the IEMs to fit comfortably in your ears, but it is easy enough to do with a pair of scissors. Try inserting them relatively gently until you've gotten them to the correct length for your ears (I tried it not so gently at first and that was not a good idea). After cutting them to the correct length for me, I have no complaints: they feel good, stay in my ears easily, the isolation works (I can't really say how much it isolates but it feels like the difference between uncomfortably loud and acceptable volume at least in some cases), the audio from the IEMs sounds good, and I can even comfortably fit a pair of protective earmuffs over the IEMs for another layer of attenuation, which I like when playing drums to keep the backing track audible at a lower volume.
If your ears are very small, it might be difficult to get them short enough without making them so short they don't work properly anymore. For my ears, it's barely doable, but if yours are much smaller than mine, it might not be. They're not very expensive though, so in my opinion it is potentially worth it to give them a try even with the caveat that they're not guaranteed to work for everyone.