I read the description at the top of the page: It also works well for all popular smartwatches, such as Samsung, Huawei, Garmin, Amazfit, LG, Pebble, etc. Small print at the bottom of the listing says it does not work with Galaxy 4. I saw the Samsung name and didn't read all the other information. I would call the Galaxy 4 a popular smartwatch. You are right. It does not fit.
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