Our CM-1702 is designed to test TWO Technicians', their wrist straps, their impedance and continuity to a reliable ground on a continual, on an ongoing basis. Should the Technicianís primary grounding fail the CM-1702 provides an immediate visual and audible alarm. The unit may be adjusted for impedance and resistivity limits and contains an on/off switch. Each unit is provided with a NIST calibration certificate. This unit is not designed for use in testing ESD matting.