[Size]: 50mm/60mm/70mm/80mm/90mm/

[Usage Method]: Hold the magnifying glass in your right hand, ensuring that the lens is parallel to your line of sight (best when the distance is clear and the magnification is maximum). With your left hand, hold the object you want to observe against the light source and slowly move it towards the lens. As you move the object being identified, find the best observation position, and the effect will be very obvious.

The imaging principle is that optical lenses made of curved-surface glass or other transparent materials can magnify objects and form images. The light path diagram is shown in Figure 1. For objects AB within the focal point F of the object, with a size of y, they are magnified into an imaginary image A'B' of size y'.
Magnification of a magnifying glass
Γ=250/f''
In the formula, 250 represents the distance at which the object can be clearly seen, measured in millimeters.
'f'-- magnifying glass focal length, in units of mm
The magnification refers to the ratio of the angle of view of an object observed with a magnifying glass at a distance of 250mm to the angle of view of the same object observed without a magnifying glass.

Reminder: The above price is based on a 70mm dragon-handle diameter. For the price of other similar products, please contact us directly.