The new NVX XTGSP2 is perfect for safely troubleshooting and testing audio systems. Offers an output range of 0-8 volts at a variable 13 to 10 000 Hz tone for setting system levels checking speaker x-over points verifying connections and general trouble shooting. The XTGSP2 also has a 9v speaker popper for visually testing speaker connection polarity. Connections can be made via supplied RCA or alligator clips. It features an auto shutoff for extended battery life.