something similar to this... sry, only link i could find in a hurry
http://cgi.ebay.com/Stinger-Digital-Blue-Voltage-Meter-Amp-Amplifier-SVMB_W0QQitemZ170016121366QQcmdZViewItem
http://cgi.ebay.com/Stinger-Digital-Blue-Voltage-Meter-Amp-Amplifier-SVMB_W0QQitemZ170016121366QQcmdZViewItem
