Connect this intercom Audio Filter to your intercom to reduce noise generated through the charging system/power supply.</br></br> Alternating current fluctuations from any electrical components/accessories contribute to communication noise and disruption. Using the simple plug-and-go Audio Filter improves communication for your intercom.</br></br> Simply install the Audio Filter inline on the power lead to your component and instantly hear the remarkable results. The Audio Filter is an affordable accessory that provides profound audio improvement and provides great value for your small investment.</br></br> IMPORTANT: For non-Rugged brand intercoms, make sure you check your power supply connections prior to installation. Other models may have reversed power leads.