Review on 📦 50-Pack DIY Jewelry Box Furniture Hand Craft Golden Hidden Hinges - Brass Concealed Hinge (0.98"x0.2" / 25x5mm) by Michael Ward

These are good economical hinges for small boxes etc with some limitations. I haven't had any issues with pins falling out as mentioned in some reviews, but the location of the pivot pin hole varies widely. Some of them are far from the hinge column, while others are roughly in the middle. See photo for centered and offset holes. This forces you to manually select pairs with a hinge pin in roughly the same place, otherwise the lid or door they attach to will open crookedly or bind slightly. It shouldn't be a problem for the manufacturer to center the holes on the post - it's just poor setup or poor tool choice.