Avialable with 2.7 V vacuum, halogen illumination or innovative 3.7 V LED illumination for higher contrast and improved diagnosis. Dioptre disc with 18 corrective lenses (+/- 1,2,3,4,6,8,10,15 and 20 dioptres). Easy to use aperature wheel with six different aperatures (fixation star, large circle, small circle, red free filter, blue filter, semi circle). High performance optics with aspherical condensor lense. Spectle protection. Parrallel optical path. Dust protected.