A. Neutral Density filter: Also known as neutral density filter, it is used to filter light. This filtering effect is non - selective. The Neutral Density filter's ability to reduce light of various wavelengths is equal and uniform. B. Adjustable Neutral Density filter: Rotating ring between ND2 - 400 gives great versatility in changing light. It reduces the amount of light without affecting colour balance. C. Features: It allows the use of slow shutter speeds on high - speed films or digital cameras to record movement/image blur in waterfalls, clouds or any fast - moving subject. The slim rim design helps to prevent wide - angle vignetting. D. Function: It eliminates overly bright and faded images. It enables slow shutter speeds to record movement in subjects such as waterfalls, providing a silky smooth effect to flowing water. E. Material: The Neutral Density Filter is made of optical glasses and an aviation aluminum frame for durability. F. Specification: 1. Type: Adjustable Neutral Density Filter/Neutral Density filter 2. Shape: Round 3. Model Number: ND2 to ND400 4. Color: black 5. Material: aviation aluminum frame 6. Lens material: optical glass 7. (1) Neutral Density 2: It can reduce the 1 stop aperture and 50% of the light quantity. 8. (2) Neutral Density 4: It can reduce 2 stops of aperture and 75% of the amount of light. 9. (3) Neutral Density 8: It can reduce 3 stops of aperture and 87.5% of the amount of light. 10. (4) Neutral Density 400: It can reduce the amount of light of 9 stop aperture, suitable for long - term exposure during the day and shooting the sun. G. Package Includes: 1. 1 Piece Neutral Density Filter 2. 1 Piece Plastic Box H. Note: This Neutral Density mirror is suitable for long exposure in low - light environments. It is not very suitable for strong - light environments. Only ND2 - 64 can be used during the day, and those above 64 are more suitable for use when the light is dark at night.