The Lee Seven 5 Polariser has been made with a unique clip-on design & can be snapped onto the front of the Seven 5 filter holder (not included, available separately). The Seven 5 Polariser filter means that you can significantly reduce reflections & glare from non-metallic surfaces. The Polariser also enables colours to become more saturated & appear clearer with better contrast. This effect is often used to increase the contrast & saturation in blue skies & white clouds. Lee Seven 5's polarising filters do not affect the overall colour balance of a shot. No adapter ring is needed for the Lee Seven 5 Polariser.