This LEE Filters 105mm Circular Polariser removes unwanted reflections from water, glass or nonmetallic surfaces. They can also be used to saturate colours and improve contrast.
The effect varies by rotating the filter and its orientation to the sun. This polarizer attaches to the filter system by an Accessory Ring (sold separately). It can be rotated independently and makes an ideal setup for landscape photographers where an arrangement of several filters may be necessary.