First pair of loupes from this company worked great. After three years they started to break so I bought a new pair. They have changed the design of the frames, and butterfly light, and this somehow, does not coincide with the working distance. I had to have the working distance adjusted a couple of times. It took forever to get back to me and I had to constantly contact customer service to see where my loupes were. I finally received them, and they’re still not 100% right and my eyes are starting to hurt from trying to move my head back-and-forth trying to adjust. The new frame design and the way the lenses are mounted are not the same.