These compact binoculars have a powerful zoom thumb lever by the right eyepiece that allows you to zero in effectively. The rubber armouring means they can survive the rigours of outdoor use pretty well, but you can also use them with a tripod. If you wear glasses, the eye relief (the distance you can have them away from your eyes) is 13mm.They have a right eye dioptre that allows you to compensate for any differences in the strength between your left and right eye. Once you have adjusted for this you can use the centre focus knob. The combination of Porro prisms, a 25mm lens plus 3.5mm exit pupil (the lens close to your eye) and Ruby multiple coatings on the optics allow enough light to get through making images bright and clearer. 367gBAK-4 prism glassMagnification 9x-27xClose focus 6mField of view - 70m @ 1000mCarrying caseLens coversNeck strapLens cloth