This Brooks-Range 10x magnifying glass with inch and metric scales folds flat for compact storage. Great for use outdoors for snow studies.
 
Features:
Uses a one-inch glass lens for distortion free viewing with inch and millimeter scales on the perimeter of a 1-inch square viewing area.
 
Dimensions:
Opens to 1.875″ x 1.5″ x 2.25″ (4.76 x 3.8 x 5.7 cm), or folds down to just over half-inch high