The focal length of a magnifier is fixed and cannot be changed mechanically, but a clear image can be obtained by adjusting the object distance (the distance between the magnifier and the object).

1.8X, The observation object distance is 3-6CM, and the optimal observation object distance is 5CM.

2.15X, The observation object distance is 2-6CM, and the optimal observation object distance is 2-3CM.

3.23X, The observation object distance is 1-6CM, and the optimal observation object distance is 1-2CM.

Operation Steps:

Place the magnifier over your eyes.

Hold the object still and slowly move it back and forth until the image is clearer.

Attention: During movement, if the magnifier is too far from the object (beyond the observation distance), an inverted real image will be formed, and the image may even be unclear. This does not meet the requirements for magnified observation and cannot be enlarged.

Features:
Crystal clear acrylic lens and double polished with 3 magnification options, no distortion but high clarity.
High brightness LED lights with dimmable switch, flexible to adjust desired illumination brightness for better viewing effect.
Suitable for examining and reading small print in newspapers, documents, maps, coins, stamps, electronic components, jewelry, photographs and pill bottles, or for repair work on watches, mobile phones, etc.
Ideal gift for seniors, hobbyists and professionals, thoughtfully provides helpful assistance for visual impairment.

Specifications
Material: ABS + Acrylic lens
Color: White
Lens Magnification: 8x, 15x, 23x (Use 2 lenses at once)
Lens Focal Length: 62mm, 33mm, 21mm
Battery: 6* LR1130 (batteries included)
Light Source: 2 * LED light
Unfolded Size: 175* 155* 55mm
Folded Size: 85* 155* 55mm

Package Included:
1* Magnifier
1* User Manual

This product has three magnifications, but only two lenses. The other magnification is the sum of the lenses.