The 3465A is a 4.5 digit bench multimeter from Agilent. A multimeter is an instrument used to test and measure alternating current (AC) or direct current (DC) voltage, resistance, and electric current. Multimeters combine voltmeters, ammeters, and ohmmeters. Electricians use multimeters to run diagnostics on batteries, switches, components, power sources, and motors.
The Keysight/Agilent/HP 3563A Signal Analyzer is excellent for analysis of low frequency signals such as audio and mechanical systems including structural dynamics and machinery vibration.
The 54003A is a probe from Keysight/Agilent/HP. Probes can use pulse waveforms to test components without removing them from circuits with in-circuit capabilities