The series GCM-04/05 of Self-Centering Lens Holders offer a reliable and self-centering mechanism for any round optical components. They are very useful when optics of variable diameters must be interchanged frequently and the height of the optical axis must be kept unchanged. Moreover, Adjustable Self-Centering Lens Holders GCM-05 can also be tilted relative to the X or Z axes through ±4º.