Fixed Filter Mounts are ideal for a variety of filter sizes, as well as for mirrors, beamsplitters, etc. The low-profile design ensures limited obstruction of the aperture. The mounts feature a non-marring surface with a M6 x 1.0 mounting hole. Fixed Filter Mounts are constructed of black anodized aluminum and are available in 3 sizes: 15mm Sq., 40mm Sq., and 80mm Sq. Posts and Post Holders are required for mounting to a breadboard.