The device works. I have a narrow ear pass, but this thing is hard but overlapping. Used the smartphone Xiaomi Mi Max 2. the app installed recommended by the seller. It all worked right away. Image of good quality at a distance of 2 cm approximately. You can not only look at the ear, but also various small details.
great product. exactly as described. easy to set up - just plug it in to your phone. the picture quality is great for the price and size (sample pic attached). very short focal length and dimmable led light make it a useful tool. the only two downsides i've found so far: the attachable hook doesn't really fit into the hole. and the shipping was very slow (but the seller communicated well and extended the buyer protection without any hassle).