A Precision Interference Filter that efficiently transmits (>80% in the range from 350 to 480nm) the light appropriate to cure dental and other blue sensitive epoxies, as well as appropriate to excite FITC and other Blue dyes. The filter will also work well to excite fluorescent dyes such as CFP or fluorescing nanocrystals, called Quantum Dots. The filter passes most of the mid blue light, yet attenuates the longer wavelengths through 700nm.  The filter will be provided with spectral data. Specifications follow: Cut off Wavelength, 480nm +2-2nm; Reflection wavelength, 490 to 700+nm; Size, 24.5mm; Thickness 2mm.