Video Isolation Transformers(VITs) work best where interference is caused by large differences in ground potential (20 volts or more). These units actually break the ground connection in video transmission to eliminate the 60Hz hum caused by ground loops. The VIT’s dielectric withstanding voltage is over 500 volts DC. In addition, the VITs are true isolation transformers with no DC path between the windings. Frequency response is flat over the range of 20Hz to 4.5MHz. Hum reduction- Video Isolation: 100 M minimum.