If you can't see it you can't impression it! The Head spec's are multi-purpose magnification glasses with dual light sources and head harness. The Head spec's give you 4 different magnifying choices and 2 lights. Just flip the lens of your choice in any combination to achieve the magnification level necessary for the task at hand.  Ideal for impressioning, close observations, precise inspections, miniature parts, assembly, detail work, circuit boards, reading and more! Magnifications available: 1.8x, 2.3x, 3.7x, 4.8x.I Uses (2) AAA batteries per light. (Batteries not included)f.