Improving visibility through certain kinds of fog or haze Used to capture the highest quality pictures in typical outdoor lighting Particularly important for long-distance photography on the ground where the detail of distant objects is often obscured by haze Generally increases the contrast of the distant objects and thus the amount of detail that can be seen Metal and optical glass with rotating frame female thread on top to allow use with other filters or hoods Product Dimension: 6.9 x 6.9 x 0.6cm, net weight: 17g Package Dimension: 11.3 x 9.4 x 1.6cm, weight: 72g