The tiffen 77mm digital neutral density filter kit includes the following 1x tiffen 77mm nd 06 2 stop filter 1x tiffen 77mm nd 09 3 stop filter x1 tiffen 77mm nd 12 4 stop filter and a storage pouch neutral density filters are designed to reduce the amount of light passing through the camera lens without changing the colours of the scene they are often used in bright conditions when capturing landscapes or using long exposures to capture blurred motion effects eg for waterfalls