These Bausch & Lomb Hastings Triplet Magnifiers use three separate optical glass lenses bonded together to form a compound lens capable of providing sharp, distinct, distortion-free images.
Each lens is made of different types of glass to reduce chromatic and spherical distortion, and has been ground and polished to instrument-quality standards.
Lens edges are coated black to block out glare. The swing-away, nickel-plated brass case protects the lenses and serves as a handle.