The FEI Helios 660 dual-beam microscope combines a monochromated field emission scanning electron microscope (FE-SEM) with an advanced focused ion beam (FIB) column for fast, precise nanomachining and nanoscale structural characterization. Enhanced capabilities include nanoscale positioning and in situ electrical measurements using a Kleindiek four-probe system with rotating grippers and a dedicated low-noise vacuum feedthrough to take electrical signals from the substrate to a parametric tester located outside of the vacuum chamber. The tool supports a variety of substrates ranging from 150 mm diameter wafers down to small pieces.