The Zurich Instruments HF2LI is a dual-input channel lock-in amplifier that meets a wide range of application needs for test and microsystem prototyping. Not only does the instrument offer high performance, it is capable of simultaneously analyzing incoming signals at up to six frequencies, making it applicable to techniques such as microfluidic-based impedance spectroscopy. The unit is used in combination with a standard Windows controller, through a USB 2.0 high-speed host connection. It includes a flexible graphical user interface and programming interfaces.