The inspection endoscope is a very useful, sometimes indispensable tool for carrying out inspections and repairs in narrow or difficult-to-reach spaces. The possibility of using it by connecting it to the smartphone is certainly an option that can facilitate its use. On the other hand, holding the phone in one hand (without the ability to rotate the screen for a larger image and with the only option to "speculate" the image with a button on the screen) and in. is not an immediate operation the other to hold the rigid cable, and perhaps a fixed screen at the sealing point would make things easier. Also because the images, although declared in HD, as you can see in the photos, are not so sharp and precise, the endoscope does its best by increasing the brightness to the maximum (even in light). For clarity, I have included the photo taken by the endoscope in the library and the photo of the endoscope taken by the mobile phone while taking the photo, so that you can understand the distance and light with which it was taken. The last photo is the clog under the bookshelf with maximum brightness. In short, average value for money, average ease of use... AVERAGE RATING! I just want to add that this endoscope could be a fun gift for curious children with a good imagination: who wouldn't have wanted such a device as a child? Unlike (fake) X-ray glasses...