The Peak TS20010 Pocket Non Measuring Microscope has a monocular eyepiece for magnification and field of view with a glass lens that provides distortion-free magnification and color correction. It is 12.7 mm (0.5 Inch) in diameter and 127 mm (5 Inch) in length, has a clip for attaching to a pocket, and comes with a carrying case. - Microscopes are instruments used to enhance the resolution of an object or image, pocket pen-type microscope is used for specimen examination in classroom, field, and manufacturing settings. A pocket pen-type microscope is used for specimen examination in classroom, field, and manufacturing settings.