This seires is designed for Sound Devices 302 and 442 mixer linking via the Tape Out/Mix Out to Mix In connections. Although commonly used for 442 and 302 mixer linking, it also may be used to connect 442 direct outputs to 744T and 788T TA3 inputs. It may also be used for RX Emergency into Mix In of a SD302 or SD442 mixer. Equivalent to Sound Devices XL-1B.