The Urth 39mm ND2 400 (1 8.6 Stop) Variable ND Lens Filter is a high-quality screw filter specifically designed for photographers and videographers who seek precise control over the exposure of their shots. With a diameter of 39 millimeters, this neutral density filter is ideal for a variety of lenses. The filter allows for a reduction in the amount of light hitting the sensor, enabling longer exposure times and improved depth of field. This is particularly useful in bright environments or when capturing moving subjects to create a smooth motion blur. The variable ND range from ND2 to ND400 offers flexible adjustment of light transmission, allowing users to tailor the exposure according to lighting conditions. The Urth ND filter is a valuable addition to any photo or video gear, supporting creative expression by allowing for manipulation of light and shadow.