The 1.25" Infrared Blocking Filter is designed by Lumicon and intended to "bracket" the color-corrected band of refracting telescopes. Use the Infrared Blocking Filter as a visible filter as well when astro-imaging with reflecting telescopes. 

Most digital/CCD cameras have built-in infrared filters, in which case the Infrared filter may be used. The Infrared filter blocks wavelengths shorter than about 400 nm. If your camera does not have a built-in infrared filter, the Infrared Blocking Filter is recommended, which blocks all wavelengths longer than 750 nm. This filter is specifically designed as an IR blocking filter.