Eyepiece Orion Sirius Plossl 9.5mm Orion Telescopes & Binoculars · Sirius Plossl 9.5mm Key specifications Focal length9.5 mm Apparent FOV52 ° Barrel size1.25" All specifications Elements4 About 9.5mm 52-degree Plossl eyepiece; Orion's standard 4-element Plossl line.