Our Custom Through the Lens (TTL) loupes are precision made to align to the user's facial features. Our proprietary True-Fitâ„¢ Digital Measurement System takes customization and alignment to the next level. Digital measurement makes traditional measurement more accurate and adds an entirely new level of measured features for optimum loupe placement. Working distances are set to the nearest 1/2" or centimeter for our international customers so each loupe conforms to the user's normal working position without forcing the user to adjust to an off-the-shelf focal distance. All working distances are 10-26 inches customized for each person.