The hand-held glass-lens magnifier K-2000 has a diameter of 75 mm, one lens, and a magnifying power of about 3.5X (10 diopter). The K-21000 has the same dimensions but has two lenses and is aplanatic. The aplanatic magnifier has a much better and sharper image than the K-20000 (see picture). This magnifier has the same dimensions (ø 75 mm) and magnifying power (about 3.5X (10 diopter).
The pocket magnifier K-4o000 has a glass lens (ø 45 mm) in a leather case.
The folding magnifier K-41000 has a black plastic case but glass lenses (aplanatic) with a diameter of 20 mm. De magnifying power is 10X.
The metal folding magnifier known as a "linen tester" has a magnifying power of 8 (32 diopter) and a glass lens with a diameter of 15 mm. The opening in the bottom plate has is 20 x 20 mm and unfolder the magnifier is 33 mm high. Folded the magnifier has dimensions 37 x 28 x 11 mm (l x w x h).