Essential in finding objects at low power for polar alignment or quick spotting, Viewfinders are basically like half a binocular. Properly align the finderscope to the eyepiece, so that whatever you see in the finderscope, will be in the eyepiece.
When the object is found with the findescope, use a higher power eyepiece which will refine the alignment.
This Meade #545 Viewfinder is standard equipment on the Deluxe Dobsonian telescopes. Viewfinder bracket is included in this version.