Bausch and Lomb model 81-31-49 N8869 This product called a "Linen Tester" is a strong magnifier with a measuring scale and a built-in stand. Historically they were, and still are, used to check the quality of woven fabrics (hence the name). They are also used for a range of projects, e.g. small detailed embroidery, art, or jewelry etc. Power: 5x Lens diameter: 1" Focal distance: 2" Rigid plastic case A vintage product but in excellent condition with the original box