The R&S®ZVAX24 extension unit for the R&S®ZVA simplifies advanced measurements on active devices such as amplifiers. Depending on the measurement tasks, it can be configured with combiners, harmonic filters, pulse modulators or high-power couplers. It is directly controlled by the R&S®ZVA via a graphical user interface. The combination of an R&S®ZVA and the R&S®ZVAX24 behaves like a fully integrated single box. However, if multiple R&S®ZVAs are being used in a lab, they can share the extension unit. This leads to an optimum utilization of investment.