... germicidal lamp ,150W, double-ended, OD 25mm, ozone produce, ozone free, tube length is 1199mm For exampleZW13D12Y-H164 stands for:UV germicidal lamp,13W,single-ended ... 1554MMFor exampleZW65S15Y-Z1554 stands for:UV germicidal lamp,150W,double-endedS,OD 15MM,ozone produceYozone freeW,tube length is 1554MM Double-ended one pin UV germicidal lamps