Powerful three-element 30 power x 21 mm jewelers loupe in a polished metal housing with a leather case.
Triplet Lens Design: A triplet lens is an optical device consisting of three single lenses. The triplet design is the simplest to give the required number of degrees of freedom to allow the lens designer to overcome all Seidel aberrations. Aberration leads to blurring of the image produced by an image-forming optical system.
