These filters are available in many sizes. The 58 mm fits perfectly on my Nikon 50mm 1.4 lens. Like all circular polarizing lenses, once mounted, it turns to provide different levels of filtration. The mount is thin, so this takes a little getting used to, but the glass is fine quality and the results are nice. In certain kinds of light, it enriches color. It's especially good for clouds and water. (If you haven't used the kind of filter before, be aware that it does cut down the amount of light reaching your sensor, especially when turned to maximum. Steady your camera.

The set comes in a nice storage box with a drawstring fabric pouch and metal caps for the front and back of the filter unit. The metal caps protect the glass from dust and scratches during transport and storage. Some might like to use the front one while shooting. I don't like it myself. It's very protective, but it's too hard for me to fiddle with when I want to grab a light effect. My regular snap-off lens cap works fine on the front of the filters.

Very nice filters! Arrived quickly in fine shape. I'll use them a lot for winter landscapes this year.