These filters are available in many sizes. The 58mm fits perfectly on my Nikon 50mm 1.4 lens. Like all circular polarizing lenses, it provides varying degrees of filtration once mounted. The mount is thin, so this takes some getting used to, but the glass is good quality and the results are good. In certain types of light, it enriches the color. It's especially good for clouds and water. (If you've never used a filter like this before, note that it reduces the amount of light reaching your sensor, especially when set to maximum. Hold on to your camera.

The set comes in a nice storage box with a drawstring cloth bag 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 may like to use the front one when taking photos. I don't like it myself. It is very protective, but I find it too hard to mess with when I want to achieve a lighting effect. My normal removable lens cap works fine on the front of the filters.

Very nice filters! Arrived quickly in good condition. I will be using them a lot this year for winter landscapes.