For example: Agilent E4440A or Anritsu 68369
Accessory
Accessories in the realm of test equipment encompass a wide range of supplementary components, including probes, cables, connectors, adapters, and fixtures, which enhance the versatility, functionality, and connectivity of the main testing instruments.
Keysight / Agilent 14565B
Device Characterization Software with Test Automation

Manufacturer: Keysight / Agilent
Keysight / Agilent 15442A
Cable kit: Quantity (4) 36" SMA (m) to SMA (m)

Manufacturer: Keysight / Agilent
Keysight / Agilent 16058A ACC
Accessory for the 16058A Test Fixture

Manufacturer: Keysight / Agilent
Anritsu 2000-1637-R
PIM Master™ Accessory Kit with 2.75 m Armored PIM Test Cable

Manufacturer: Anritsu
Wandel and Goltermann 2234/01
SDZ-30 SIGNAL BALANCE RATIO BRIDGE

Manufacturer: Wandel and Goltermann
National Test Equipment 2436NC
Metro chrome wire carts (2436NC)

Manufacturer: National Test Equipment