... .1mm,40-20 Clear Aperture: >85% of dimension wedge, penta, roof, dove, right angle optical prism Specifications1.high quality 2.high ... of glass prism, Prisms are blocks of optical material with flat polished sides arranged at precisely controlled angles to each other ... prisms, tapered prisms, littrow prisms, reversion prism, Pellin-Broca prisms, Roof prism, Rhomboid prism as well as your design.