When open, the cut out square on the base is marked along all four sides in Imperial or Metric scales. (It is still a surprise, or is it, that we sell ten times as many Imperial models than Metric)! This enables the number of threads and weave to be counted to the inch (or centimetre) and therefore to determine the quality and strength of the material.
Lightweight and comfortable in use, the OptiVISOR is designed for people who need to see minute detail clearly. æAlso included in this offer is the VisorLIGHT and the OptiLOUPE for a discounted price.