Product Name: Life Jacket LightsModel Number: yYD1, YD2, YD3, YD5, YD8, PH2703BPlace of Origin: ChinaFeatures: 1) Operation time: at lest 8 hours 2) Luminosity intensity: at lest 0.75cd 3) Chromaticity: white 4) Flash frequency: 50 - 70 times/min 5) Used in sea and river life jackets 6) Validity: 3/5 years 7) Battery: lithium battery ( PH2703B is using seawater abttery) 8) The lights are flash, expect YD2