Signal-conditioning module provides two instrumentation amplifiers ideal for low-level signals such as bridge circuits (e.g. strain gauges) and thermocouples. Each amplifier converts a differential input to single-ended. The LJTIA has switches to choose from 5 gain settings (x1, x11, x51, x201, or custom) and two output voltage offsets. The 4-pin design plugs into the standard AIN/AIN/GND/VS screw terminal block found on newer LabJacks such as the U3, U6, UE9, and T7.
The LJTIA datasheet has more information.
The U12 has been an absolutely essential piece of hardware in my experimental projects. It's performed exceptionally well and I've recommended the device to several of my colleagues.—Brendon, Electrical Engineer