Iris diaphragm holder for holding lenses up to 75mm dia. A fast and convenient means of mounting lenses with an advantage that no light passes except through the lens. The optical component is automatically centered by holding it in the diaphragm. It is operated by a projecting pin which slides circumferentially. With Post, Post holder, Collar and Base Plate. Material – Anodized Aluminium. Available in different diameters.