The DSI-2008 dual digital hybrid interfaces two two-wire intercom lines to two four-wire lines, and also interfaces balanced and unbalanced two-wire lines. The DSI-2008 is ideal for systems with varying loads. (Amount of user stations often vary for different configurations.) Unlike earlier analog hybrids, the DSI-2008 features advanced digital signal processing to achieve automatic nulling of the two-wire lines. In addition, each hybrid features convenient peak-reading level meters to quickly match the levels between the lines that are being interfaced. The result is easy and accurate setup. With the DSI-2008, all need for test tones; nulling adjustments and ducking adjustments have been eliminated. In addition, there is a call light option board available for compatibility with RTS Two-Wire Intercom and Telex Audiocom systems.