Abstract: A device comprising a housing, at least one optical component, such as, for example, a polarizer, contained in the housing, and a base. At least two fixing means are attached to the housing and at least one fixing means is attached to the base. The at least one optical component is fixed at a predetermined position upon mating of at least one of the at least two fixing means attached to the housing with at least one fixing means attached to the base. Such device provides for more precise optical measurements than devices which include optical components that are rotatable through a continuum of angles.