Inline Audio Filter for Intercoms reduces noise generated through the charging system/power supply. This noise is often caused by alternating current fluctuations from any electrical components/accessories, leading to disruption in communication. Once the Audio Filter is installed inline on the power lead, you can immediately experience the profound audio improvement. It comes at an affordable price and yields significant value for your investment. However, for non-Rugged brand intercoms, you must check your power supply connections before installation as other models may have reversed power leads.