I bought several on Amazon and returned them all... junk, albeit all under $100.
I asked my dental hygienist what she uses because she uses them continually all day. It turned out to be made by a company in Reno, but the loupes were $1000 to $2500 and the LED add-ons are around $600 more so it ends up costing a few thousand. Lumadent. Another good one to check out is Orascoptic.
I couldn't justify the expense for my needs so I just use some 3X reading glasses and a 10X handheld loupe when I need it.
