UV Protective Filter: Prevents loss of sharpness and contrast by filtering out UV rays and Haze. Protects Lens from scratches, scuffs and smudges
CPL Circular Polarizer Filter: Uses Polaroids patented Polarizing technology to give you total "on location" control of color saturation, make skies bluer-even eliminate surface reflections from glass and water - all with perfect results
ND9 filter has a 0.9 solid optical density and it can also increase exposure length