Binocular Headband Magnifier, professional. £140.00 to £290.00
There are two reasons this is recommended for dentists, professional art renovators, engineers, watchmakers etc.
Firstly, the quality. The image is SO crisp and sharp and bright that even I am impressed, and it takes a lot to impress an optical dealer!
Secondly, the padded headband is easy to collimate (set up) for your eyes and comfortable to wear for many hours. The headband may LOOK over-elaborate, but it is lightweight, easy to adjust and sturdy, better than spectacle-mounted magnifiers which can slide down the nose after a while.
2.5X or 3X are suitable for most applications, 4X is very powerful and would only be used for VERY small objects such as small wrist watch movements. As for 6X, perhaps there are some uses: for untangling a very small hairspring? For working on the smallest of micro-circuits? For dissecting tiny insects? Please do not automatically choose 6X, it is too powerful for most uses.