Abstract: A selective aperture for a laser delivery system for providing incision, ablation and coagulation. A laser crystal disposed between two reflective surfaces forms a laser beam. An aperture member positioned between the laser crystal and one of the reflective surfaces includes a substantially circular aperture for passing the laser beam. The size of the aperture is selectively adjustable. The aperture member has a plurality of apertures of various different sizes and is rotatable about an axis of rotation. The axis of rotation is parallel to the longitudinal axis of the laser crystal. By appropriately rotating the aperture member, a selected one of the apertures is positioned to pass the laser beam. A stepper motor and flexible shaft are utilized for rotating the aperture member. At least one of the apertures is surrounded by a beveled portion of the rotatable member. Alternatively, two lasers with different size fixed apertures could be utilized and directed to a common surface.