Review on High-Quality Triplet Jeweler'S Loupe With Chrome Finish And Leather Case - HTS 203E0 20X 21Mm by Tre Boyer

I got this for an aspiring geologist friend of mine and I was very disappointed. The lens is large (and weighty) but offers only a small field of view that is actually in focus (less than half the diameter of the lens). What is worse is that this lens can only be used if you are looking through it from one side (the lens will be touching the mineral sample before you get it in focus if you try it the other way around). I have honestly never encountered such a bad hand lens. I would never purchase this lens again. If you are looking for a good hand lens (particularly for geology) I would recommend paying a little more and getting a Bausch & Lomb lens. They do cost more, but if you are planning on having it throughout your career, it is definitely worth the minor investment.