The achromatic optics consist of three lenses in two groups. 13 different scales are available for this Peak magnifier (1975) in black text or 3 scales available in white text (black background). The optics have been treated with an anti-reflex coating. Specifications: Magnification 7x Achromatic Optical Oystem (3 lenses in 2 groupes Field of view: Ø24 mm Dimensions: 36 x 62 mm Weight: 52 grams Fine focus Perfect illustration of object - distortion free Light admitted through transparent body Standard scale/reticule included (pic 3) (Scale division 0,1mm, length 10 mm)