This tertiary protector takes advantage of the saturation characteristics of the transformer and is thus rated only for 50A based on the 8/20µS current surge generator. Since it is not located on the line side, it does not need the higher 100A 10/1000 type rating that the line side will endure. Difference DSL implementations will use different drive voltage levels; therefore there are four different components to choose from. The VDRM value is decided by the DSL PHY drive voltage, and one must take care to note if the DSL PHY driver uses a charge pump that can drive the voltage levels higher than the Vcc supply. The low capacitance of this component makes it compatible with ADSL2, VDSL2 and even g.fast.