Having noise issues with your radio and intercom setup? Connect this Audio 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 Audio Filter improves your communication for both your intercom and/or radio. Simply install the Audio Filter inline on the power lead to your component and instantly hear the remarkable results. The Noise Filter is an affordable accessory that provides profound audio improvement and provides great value for your small investment. IMPORTANT: For non-Rugged brand radios and intercoms, make sure you check your power supply connections prior to installation. Other models may have reversed power leads. Does not work with the RM25R-WP.