When the maximum possible clear aperture is required, the best choice is elliptical flat mirrors. Due to unique geometry of substrate, the aperture becomes circular when mirror is rotated by 45˚ around the minor axis. List of standard mirrors contains 16 different items. 4 different sizes, scaling from 12,7 mm up to 50,8 mm, and 4 types of metallic coatings are availabe. The most common aluminum coating features a fair reflection in UV, visible and mid - IR wavelenght ranges. Protected silver coatings assures the highest reflectivity of all metal coated mirrors in the visible wavelength range. Protected gold is the most efficient coating over the entire IR range. However, if higher reflectivity is needed, the best choice is dielectric coated elliptical mirrors; Laserand can also offer such custom solutions.