A lens holder is a product for securing a lens. There are various types used for optical experiments. The feature of the rigid type is that it is simple, only securing the lens with the screw ring method. There are many types, from large to small. The centering lens holder has a centering mechanism that aligns the center of the lens, and is available in a dovetail type or with cross rollers. With the coaxial type, the lens is fixed at three points, and the optical axis is constant even if the lens is changed, eliminating the need for adjustment. In addition, there is a type that has an adjustable 5-axis and a type that can adjust the lens 3 ways manually.