ZVR and ZVC comprise a test set with two SWR bridges (ZVR) or directional couplers (ZVC), an RF switch, two measurement channels and - unlike ZVRE and ZVCE - two reference channels. With this configuration a variety of novel calibration procedures, eg TNA, can be performed, which considerably improve the accuracy particularly in non-coaxial applications. ZVR and ZVC are the allrounders of the family and suitable for applications in R&D and production no matter how sophisticated.