The 9897 Flip-Up™ Filter Holder lets you quickly insert or remove 1.0 in. (25.4 mm) diameter filters in your experiment. Flip the filter into place when you need it, and then snap it out of the way. Both thin and thick optics are held firmly, using either the threaded Delrin insert or the standard setscrew (both are included). Stacking any number of Flip-Up filter holders is easy with a screw and nut. If you need to precisely align your optic, you may want to use one of our Flipper™ mounts.