5 Pcs Jewelers Loupe Portable Monocular Magnifier Magnifying Glass Eye Loops Magnifier with 30 x 36 mm Lens Watch Jewelry Experimental Repair Tool for Textile Optical Circuit Coins (5X 10X 15X 20X)

The larger one feels like it's a higher quality, and I use it almost daily. The smaller ones feel lower quality, but still function just fine.

For their price, this is an excellent set. The metal one is not a 30X lense but it gives a nice wide field of view at about 8 X. All of the lenses are clear, without major distortion.

Exactly what I wanted for inspecting coins.

The larger metal and glass optic marked "Made in Germany" is worth the whole price. It's clear and it provides a useful view. Enclosed photo shows a 2mm drill bit above a 1/8" thick piece of aluminum, looking through this lens. The other four plastic lenses are very cheaply made, but the lowest and highest mag ones are still OK. The middle two are woefully bad. They have many ripples, so if you rotate the lens around the central axis, you see wavy distortion roll around the image (eg. it has a lot of high-order astigmatism). You should never have that in something you're supposed to look through (without getting a headache). The surface seems smooth, so I'd guess the plastic composition was not uniform in the injection mold and it has irregular patches of higher and lower refractive index.

The title basically sums it up. These are very affordable loupes. And God knows we all could use a break on the cost of everything these days. So, affordable doesn't immediately mean bad. These all actually work really well. The magnification is excellent. Some might even be more than needed. I got the loupe ring for head wear, as I work on watches as a hobby.So, why the 3 stars? Just the quality. All but the large one are plastic and feel extremely cheap. No weight at all. Which, I know you kind of want that and most loupes are lighter to wear with the head wire,but these just feel like they'd easily break if you just put a tiny bit of pressure on them and one was a bit loose and rattling and I can't fix it. It's not a huge deal,they still work. If I could give it 3.5, or increments, I would. I wouldn't say don't get these. The optics are petty great for the price and they're a nice option for the beginner watch tinkerer or model builder etc. Just adjust your expectations. I recommend them.