Filter—B+W 403 Ultraviolet Pass
Graphs are in nanometers. Visible light is approximately 390 - 650 nm (the human eye can see very weakly into the 700-800nm range). Graphs used by permission of Coastal Optical System.
A great source for filters at competitive prices is B&H Photo. Get filters at B&H Photo.
Note the highly undesirable “leak” of infrared in the 700-830nm range.
Not recommended for UV work (unless you need a larger size), even though such work is its stated goal, because of the pronounced infrared leakage.
See the Baader Venus II filter.