Rosco's Strobist 55-Piece Filter Kit has most, if not all, of the color filters you'll ever need for your on-camera flash, sized perfectly (1.5x3.25") for portable camera-mounted strobes. Working with David Hobby, founder of www.strobist.com, Rosco put together a collection of 20 different Cinegel colors (including different strengths of several colors) for a total of 55 gels that cover nearly every situation where you need to filter your on-camera flash for color balancing with non-daylight sources, to change your strobe's output, and or to add a color accent. A Lumiquest gel holder is included.