... UV 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,OD 12mm,ozone produceW,ozone freeZ,tube length is 164MMFor exampleZW55D17Y-H533 stands for:UV ... :UV germicidal lamp,150W,single-endedD,OD 19MM,ozone produceYozone freeW,tube length is 1554MMFor exampleZW65S15Y-Z1554 stands for:UV ...