150mm System Square Filter Holder NiSi Exclusive Two Patents 150mm Filter Holder consist of lens mount clamp foundation and filter installation system. Ergonomic design make Lens mount clamp fixed on the lenses quickly. The Filter Holder can rotate with 360 degree. It’s made from aviation-grade aluminum with single element processed by CNC Machine. Also with matte black frosted finish on the surface. All of screw accessory are made of copper and with black nickel plating. It’s durable and can reduce the influence of stray light on the imaging.