Valtcan demand wrist strap tester that resistance of your wrist strap is no lower than 800KO and no greater than 9MO. The straightlaced resistance will an `` sanction '' semiconductor diode indication on the wrist strap tester. If either the RED `` FAIL LOW '' or chromatic colour `` FAIL sopranino '' semiconductor diode 's luminosity, and the sounding indicator sounds, then the wrist strap -LRB- or the connection cord -RRB- should be. 9V battery. Battery not. two screws on spine of unit and insert 9v battery into compartment. : The still strap function, Wrist Strap Tester can quickly and easily check the favorable : Test still strap and connection wire connection Test the impedance between skin and still strap Test the connection during anti-static access panels, cushion for connecting connection Quickly and easily check connection systems at any place fend off still electricity to damage the product Ensure staff safety Specifications : Instruction Impedance calibration : Buzzer low-toned -LRB- chromatic -RRB- : R good -LRB- greenness -RRB- : 800K ohm less R less 9M ohm ON high-stepped -LRB- chromatic -RRB- : R > 9M ohm OFF external size : 80 -LRB- W -RRB- x40 -LRB- H -RRB- x117 -LRB- D -RRB- mm Power source : 9V battery The length of grounding wire : 2.5 m .