Shell Diala S4 ZX-I is the new electrical insulating oil from Shell designed to meet the challenges presented by the latest power transformers. It offers an extended oil life with the peace of mind of zero sulphur content. Shell Diala S4 ZX-I is manufactured from zero sulphur base oils produced using Shell’s GTL (gas-to-liquid) technology. These base oils offer a high degree of compositional consistency and have an excellent response to anti-oxidant. In addition they are globally availible and free from PCBs, DBDS and passivators. Shell Diala S4 ZX-I meets both the established and new industry copper corrosion tests.