This unit was one of the best accessories I've purchased for my spotting scope! "Sighting in" the unit was quick and simple. Once sighted in, any visible object was quickly placed in the field of view of my eyepieces! Aiming the scope between the stars became a lot easier too because the red dot is always illuminated, so there's no guesswork like with a refractor finder scope. Mounting the unit took a little work but it was well worth the time and effort. If you're "point & shoot" observing, then this is a must have!