MIRROR: Download from MEGA
I've been through a customs check with a plug once before. Depending on what it's made from, you might get just a few odd looks, or maybe nothing at all. Mine for example is actually a glass one, which normally goes through without a second glance. Only once did it every actually cause a stir... but I was kind of wearing it at the time. I don't recommend doing that, by the way.
I've heard they're a little more touchy about silicon ones, though as I don't have one I can't say for certain.
And if you're thinking of taking Sebastian's advice on a good manufacturer, personally I recommend the Stockroom. I've never known anything they stock to be bad quality.
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