Sigma protector normal type is developed to protect the lens surface from dirt and dust as well as scratches it is an ideal filter for regular use as it is completely colourless so does not affect colour reproduction sigma wr protector water repellent antistatic type is also available the sigma 46mm protector clear glass filter is designed to protect the lens surface from dirt and dust as well as scratches it is an ideal filter for regular use as it is completely colourless so does not