You can get the same one from Amazon for a couple bucks more, and with Amazon it ships from the USA (not HK), and you can return it if you're not happy with it. I'd also think the chances of Amazon selling you a knock-off to be very low.
I am suspicious not because of the price or the vendor. I have had very good luck with Meritline. But the UST mirrors I have seen do not have the embedded compass. the lanyard looks to have a whistle on it, but it does not look like an UST whistle.
On the other hand, it does on the whole look a lot like a real UST mirror.
I ended up sending UST an email asking them if it is legit. Oddly, nothing on their web site actually shows a full view of both sides of their mirrors. And nothing I can find anywhere on their web site shows they sell one with an embedded compass.
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Warning - I am not an expert on anything having to do with this forum, but that won't stop me from saying what I think.
Bob