The Keysight 85130B test port adapter is designed to protect the test set port when it would be directly connected to the device under test. These adapters have a special rugged female connector designed for connecting to the network analyzer test port. This special connector will not mate with a standard male connector, but converts the rugged test set port to a connection that can be mated with the device under test. The set contains two 3.5 mm female to 7 mm adapters. The frequency range for these adapters is dc to 18 GHz with a return loss of 28 dB or better.