Model #: CO10675. Barska 12x50 Zoom Binoculars w/ Blue Lens & Carry Case, Clam. • Prism Type: Porro. • BK-7 Porro Prism Construction. The wide variable magnification range of these binoculars allows the viewer to target in on an object and then zoom in and magnify it to obtain a closer look and see greater detail.