The Revolution Ballast EMI Filter is designed to suppress the electromagnetic interference (EMI) that radiates from the cables of poorly designed electronic ballasts. EMI can interfere with the TV, WiFi, radio, and cordless telephone reception of surrounding residents, creating an unintended nuisance to neighbors. With the Revolution Ballast EMI Filter, you can address the EMI issue from inferior ballasts before it becomes a problem. Exclusively from Hydrofarm.