For Nikon PC NIKKOR 19mm f/4E ED, Haida 150 Wide-Angle Filter Holder, For Filters 150mm Wide, 2mm Thick, Holds up to Two Rectangular Filters, Rotates 360°, Gaskets for Light-Blocking Seals, Bayonet Adapter Ring, Secure Attachment to Lens, Easy Installation, Aluminum-Alloy Construction This Haida 150 Wide-Angle Filter Holder Kit is designed to allow for the convenient use of 150mm wide 2mm thick filters with a Nikon PC NIKKOR 19mm f/4E ED lens without vignetting. The kit consists of two main components a front filter holder and a bayonet filter holder adapter ring. Use of the filter holder is easily accomplished by first locking the filter holder adapter ring onto the front of a Nikon PC NIKKOR 19mm f/4E ED lens. Adapter rings are separately available for lenses with 67mm 72mm 77mm 82mm 95mm or 105mm front filter threads. After being fitted onto an adapter ring the filter holder's screw-on locking pin helps to provide a reliable yet adjustable connection that allows the holder to be rotated 360? permitting the use of graduated neutral density and other filters that are enhanced by varied positioning. This Haida 150 Wide-Angle Filter Holder Kit is pre-installed with one pair of filter slots a configuration that accommodates one rectangular filter. Also included is a second pair of filter slots and a second set of screws designed to attach both pairs which allows up to two rectangular filters to be used at the same time. To prevent stray light which could have unwanted effects on exposure from coming in between an installed filter and a connected lens two gaskets are positioned along the front of the filter holder. These gaskets are designed to form a seal between the pairs of plastic filter slots.