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

Wear the magnifying glass on your eyes.

Keep the object still and slowly move back and forth until the image is at its clearest.

Attention: During the movement, if the magnifying glass is too far away from the object (beyond the observation distance), an inverted real image will be formed, and even the image cannot be seen clearly. This does not meet the requirements of magnifying observation and cannot be magnified.

Features:
Dual polished and crystal acrylic lens with 3 magnification options, no distortion but high clarity.
High brightness LED lights with adjustable dimmable switch, flexible to adjust the desired illumination brightness for better viewing effect.
Suitable for examining and reading fine prints in newspapers, documents, maps, coins, stamps, electronic parts, jewellery, photos, and pill bottles, or repair work for clock, watch, cellphone & etc.
Ideal gift for seniors, hobbyists and professionals, thoughtfully provide helpful visual impairment aid.

Specifications
Material: ABS+ Acrylic Lens
Color: White
Lens Magnification: 8x, 15x, 23x ( Use 2 Lens in One Time )
Lens Focal Distance: 62mm, 33mm, 21mm
Battery: 6* LR1130 ( Batteries Included )
Illumination Source: 2 * LED Light
Unfold Size: 175* 155* 55mm
Fold Size: 85* 155* 55mm

Package Included:
1* Magnifier Glass
1* User Manual

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