GSO Infrared IR Cut-Off Filter (50.8mm, 2")
Infrared cut-off filters are usually being used with color CMOS and CCD cameras to produce better quality images, as these are quite sensitive to infrared (heat) radiation of light. They will also improve sharpness of the image as most of the optics are designed for the visible spectrum, because it's very difficult to create a lens with the same focal point for the visible and IR spectrum. These filters will cut off ultraviolet UV as well. (To make you well informed I tell you a secret about the latest: there is nothing surprising in it, as this is a usual property of most of the glass materials; that's why we never get tanned through a window :o) But please do not buy these filters for your night security camera that works with infrared LED, because it'll cut that IR radiation off as well.
This filter is a 2" ( 50.8mm ) filter and comes with an inner thread thus can be screwed together with other filters (e.g. saving your expensive Hydrogen-alpha filter from overheating).
Comes in a long-lasting white plastic filter box, seen on the image.