Nagler 2mm - 4mm zoom eyepiece

The smaller the focal length of an eyepiece, the higher the magnification when used with a telescope.

This is the angle of aperture of an eyepiece.

The optical elements are treated with ultra-thin coatings. Among others, there are anti-reflective coatings for reducing, and dielectric coatings for increasing reflection.

With these eyepieces, the magnification can be variably adjusted within a certain range.