A version of the cylindrical probe which can be used at high vacuum. The probe is unanodised and has had blind holes removed where possible. High vacuum wire is used for the connections which are crimped rather than soldered. A ruby ball is used for the insulation pad. All Jandel probes are built to a high level of mechanical accuracy. Specifications for radii, spacing and planarity are verified by video inspection system and optical interferometer. Loads are verified by electronic force gauge. Each probe has upper and lower jeweled needle guides.