... stands for:UV germicidal lamp,95W,single-endedD,OD 15MM,ozone produceYozone freeW,tube length is 1550MMFor exampleZW95D19Y-Z1554 stands for:UV germicidal lamp,150W ... ,single-endedD,OD 19MM,ozone produceYozone freeW,tube length is 1554MMFor exampleZW65S15Y-Z1554 stands for:UV germicidal lamp,150W ...