The Keithley 4225-RPM (Remote Preamplifier/Switch Module) is an expansion unit for the 4200A-SCS Parameter Analyzer specifically designed for precise measurements at very low currents. This module improves accuracy and resolution when measuring small signals and reduces the effects of cable capacitance and noise. The 4225-RPM is ideal for applications that require extremely sensitive measurements, such as characterization of semiconductor materials and nanoelectronics. The module allows flexible switching and supports a variety of test configurations.