Active Filter for Radio & Intercom by Rugged RadiosSKU: ACTIVE FILTER WP Having noise issues with your radio and intercom setup? Connect the Rugged Active Filter inline with your radio and intercom to suppress noise generated through the charging system power supply. Alternating current fluctuations from any electrical components accessories contribute to communication noise and disruption. Using the simple plug and go Active Filter improves your communication for both your intercom and or radio.