The enhanced basic model with separately engageable redfree, blue and polarization filters for each aperture. - Diopter wheel with 29 corrective lenses Plus 1-10, 12, 15, 20, 40 - Minus 1-10, 15, 20, 25, 30, 35 - Easy-to-operate aperture hand-wheel with semi-circle, small/ medium/large circle, fixation star, and slit - Includes filter wheel engageable for all apertures with symbol display, red-free filter, blue filter and polarization filter