Special Features:

Also includes 1 audio cable, tripod, adjt. Brightness, red blue green c olors, tones, music, tactile, visual.

Properties:

An adjustable item of thin, overlapping opaque plates which are actuated by a ring or other device so as to change the diameter of a central opening, for controlling the intensity of transmitted illumination. It is usually employed to regulate the aperture of a lens in microscopes, and other optical instruments.