This 100mm Lucroit Filter Holder with 3 x 2mm Slot Adapters from Formatt Hitech, along with a separately available adapter ring, is designed to allow threaded or threadless lenses to use multiple rectangular or square filters that are 100mm wide. Its included and replaceable snap-on slot adapters can accommodate up to three 2mm-thick filters. Optional adapters that can accommodate two 2mm-thick or two 4mm-thick filters are separately available, as well as snap-on French flags and barndoors for controlling reflections and lens flare.
Adapter rings that fit a round, threaded 105mm polarizing filter over the slot adapters are also available, with options for a 0.75mm thread pitch, or a 1mm thread pitch.
The holder can rotate a full 360°, permitting the use of graduated neutral density filters, and other filters where varied positioning enhances their use.