3M WSMONITOR2, Anti-Static Constant MonitorCondition:* Used Sales Sample. In OEM Packaging. Additional Notes:* Aluminum enclosure shields the monitor from noise emitted by fluorescent lighting* Mat monitor switch allows the mat monitor circuit to be disabled when not in-use* Meets ANSI/ESD S20.20 in accordance with ESD TR1.0-01-01* Use with Single-Wire Wrist Straps (Not Included)* NIST Calibrated with Certificate Included* 100-240 Volt AC Power Adapter with interchangeable plugs for North America, United Kingdom, Japan, Asia and Europe* Size: 1″ x 2.4″ x 2.3″* Description/Function: Monitors one wrist strap per person with the bench mat* Features: 120 Volt AC Power, 3 Prong3M WSMONITOR2