Eyepieces are needed for observing. Depending on the focal length, you achieve a certain level of magnification. The specification 1.25" refers to the diameter of the connector (1.25" = 31.8 millimetres).

Eyepieces are needed for observing. You achieve a certain level of magnification depending on the focal length. The specification 2" refers to the diameter of the connector (2" = 50.8 millimetres).

Extends the focal length and thus increases the magnification of a telescope. It is positioned between the telescope and eyepiece or camera.

Optical aid to correct aberrations.

This means a plug for the cigarette lighter socket in a car.

A telescope always displays an object upside down. This law of optics can only be compensated for by an erecting system. Erecting lenses, diagonal mirrors or Amici prisms provide you with an upright image. Diagonal mirrors provide an upright but back-to-front image and Amici prisms provide an upright and right-sided image.

A mini telescope used to locate a celestial object. There are optical finders and red dot finders.