What piece of equipment is associated with Squawk and IDENT in aviation?

The piece of equipment associated with Squawk and IDENT in aviation is the transponder. The transponder is a critical device used in aircraft for identification and tracking purposes by air traffic control. When a pilot is instructed to "squawk" a specific transponder code, they input that code into the transponder, which then transmits signals that include the aircraft's altitude and identity back to radar systems on the ground.

The IDENT function is an additional feature of the transponder, which allows the pilot to activate a signal that makes their aircraft's radar return more prominent. This is helpful for air traffic controllers to visually identify the aircraft on their radar screens, especially in busy airspace.

Other options do not relate to the Squawk and IDENT functions: a radio altimeter is used for providing altitude information above the terrain directly below the aircraft; an autopilot manages the aircraft’s flight control systems without pilot input but does not involve communication of identification or altitude; and a flight data recorder, often referred to as the "black box," records flight data parameters but does not actively transmit the aircraft's position or identity.