By far the largest selling and most widely used automotive circuit tester. Quickly checks all 6 and 12 volt systems Use with power on Supplied with 48″ ground wire Use to locate shorts, grounds and open circuitsModel #SG21000Includes: 48 in Ground Wire Shipping Details Shipping Type: parcel Free Shipping: true Specifications SUOM Description: Each Brand Name: S & G Tool Aid Description: Circuit Tester Volts: 6/12