It's probably very obvious, but since no one seems to have mentioned it, it very important that
any eartips you get fit your IEM!
If the inner diameter of the tips is too small, you won't be able to get them on (usually they stretch a bit, so it's ok if the diameter is slightly smaller than your IEMs). If the diameter is too big however, they will simply fall off, or worse get left in your ears when you remove your IEMs (this is NOT fun!).
You can can check the size before buying by:
- Checking that your IEM is listed as supported by the eartips (the Comply and Spinfit websites have an easy way to show only their tips that fit a given IEM)
- Measuring the diameter of the nozzle of your IEM, and check that your eartips say they are compatible with this diameter, or have an internal diameter that is either the same, or slightly smaller. (The length of the nozzle shouldn't be too important, but you probably want it to not be longer than eartips, or it will stick out)
- Combining the above two: check that your IEM's diameter is the same as a model that your eartips support.
In particular, my Truethear x Crinacle Zero has a very large diameter of 7mm (as opposed to my 4.5mm Sennheiser IE 200) so not as many eartips will fit them, I suspect the Gate and other Zero's are similar.