The DI-2 is a two channel version in the same sized box, for use with stereo keyboards or two separate mono signals. It can also be used as a balanced signal splitter by connecting a short jack-to-jack lead from the link socket of channel 1 to the input of channel 2.  Channel 1's signal will then be available on both balanced XLR's, and channel 2's link socket.  The attenuation switches remain working independently.