UP TO 4 TIMES BRIGHTER AND LASTS UP TO 50 YEARS - New super bright feature makes this unique ISOBrite Watch 4 times brighter than standard tritium watches and the illumination will last TWICE as long than other brands T25 watches. Size and illumination of the watch makes it easy to read.Isobrite ISO313 Valor Series is the first T100 lightweight polycarbon watch with 10 year battery life, sapphire crystal, two tritium markers on the unidirectional bezel, 200m water resistant watch on the market. The "T" rating measures the amount of tritium in a watch. The higher the rating the brighter the watch will be. All other manufacturers of polycarbon cases have a rating of T25.Why do T100 watches last so much longer than T25 watches?The Isobrite T100 watches contain approximately four times the amount of tritium gas as the T25 watches do (i.e.: Luminox, Traser, MTM). The higher volume of tritium gas results in a much brighter visible illumination combined with a much long...