Electron-optical device

A charged particle-optical device for projecting a plurality of charged particle beams along respective beam paths towards a sample location, the charged particle-optical device comprising: a charged particle-optical assembly configured to manipulate the charged particle beams, the charged particle-optical assembly comprising a first charged particle-optical element comprising a plate having one or more apertures around a beam path of the charged particle beams; and an electrical connector configured to electrically connect the plate of the first charged particle-optical element to an electrical power source, wherein the electrical connector: comprises a shield configured to define a field free region substantially free of electric fields; and is configured to be electrically connectable to a flexible coupling configured to electrically connect the plate of the first charged particle-optical element to the electrical power source, the flexible coupling located within the field free region.