The binocular has a magnification of 8x.

The magnification number indicates how many time an object is magnified by the lens. The larger the number the higher the magnification.
For a binocular with magnification 7 or 10 is most useful. When the number is higher it will result in less stability of the image.
Objective lens diameter: 21 mm
This indicates how much light is let through the binocular lens.
The bigger the lens the more light comes in but also means the binocular will be more heavy.
The field of view at a 1000 meters distance is 128 meter. Making it ideal for moving objects like birds and planes.
The binocular is best used during day time. It has an exit pupil diameter of 2.7 mm
The darker the environment the larger your pupil will become. When your pupil becomes larger than the exit pupil diameter visibility will be less clear.
A human eye pupil diameter can change from 2 mm up until 7 mm. So in case you expect use a binocular often in the dark then a high exit pupil diameter will be important. 7 mm can even be used at night. 5 mm is suitable for dusk and dawn. Under 5 mm is more suitable in day-time.
This binocular can handle an Interpupillary distance (IPD) of 29 - 69 mm
The Interpupillary distance (IPD) is the distance between the centres of the pupils of the eyes.
This is different from person to person and also depends on whether they are looking at near objects or far away
Due to eye-relief of 10.5 mm this binocular is less suitable for spectacle wearers
Eye relief is the distance from the last surface of an eyepiece within which the user's eye can obtain the full viewing angle.
If an eye relef is 11 mm or higher then people who wear glasses can see through it without taking off their glasses.
If the eye relief is lower than 11 mm you can keep on the glasses but then you need to focus the sight by the turning ring on the lens of the binocular
The Dioptric Correction on this binocular can be used to adjust the optical instrument to a person's eyes. It is the adjustment of one lens to provide compatible focus when the viewer's eyes have differing visual capabilities. Resulting in less strain on the eyes that allow for optimal viewing, depth and contrast focus.
This binocular has a Roof Prism
Lens colour: Red
Protection bag supplied 

Product specifications
Width     102 mm
Height     36 mm
Depth     92 mm
Weight     171 g
Colour     Black
Material     ABS
Rubber
Travel bag included     Yes
Protection cover     Yes
Shoulder strap     Yes
Number of Products in Package     1 pcs
Objective lens diameter     21 mm
Field of view     128 m
Exit pupil diameter     2.7 mm
Eye relief     10.5 mm
Dioptric correction     Yes
Interpupillary distance     29-69 mm
Lens colour     Red
Sharpness adjustment wheel     Yes
Cleaning cloth included     Yes
Roofprism     Yes
Magnification     8 x