Echnical specifications of the trial set: total 225 lenseslenses 0.12 to 20sph +- one pair each0.12 to 06cyl +- one pair each10 prisms upto 12.07 standard access. (2 blanks, pinhole, slit, red, green & maddox rod)size 0.12 to 6.00 dioptors 25mm reduced aperture lenses7.00 to 20 dioptors 20mm reduced aperture lenses