This Fluorodive Kit from Bigblue uses carefully selected, tempered glass filters for the optional VL1800M, VL2500P and VTL2500P dive lights to allow for improved viewing of coral fluorescence. The fluorescent proteins invisible to the naked eye jump into view when illuminated by the filtered light. With this kit, you get specially designed blue and deep blue filters to precisely match the fluorescence wavelength, and a yellow blue-barrier filter to increase the intensity of the colors emitted by the corals. The innovative snap-on and flip-open filter design allows you to easily switch between blue and white light to accommodate changes in dive conditions. The removable yellow blue-barrier filter goes over your diving mask, attaching via the included neoprene strap, in order to filter out the blue light, leaving behind only the fluorescence in green, yellow or orange colors.