This most practical device converts a variety of Zeiss ClassiC binoculars into spotting scopes. By simply attaching this 1.9 oz. gem to the binocular, it triples the magnification. Zeiss precision design assures perfect alignment of the optical channels, so you needn't worry about strain or fatigue The TripleXXX is one of the smartest, most reasonably priced accessories available. And for the record, it excels on its own as a fantastic 3x monocular, or as a 5x magnifier for close work. This model includes adapter "A" for use with Zeiss Classic Binoculars (excluding 8x30 and 10x40).