The Hosa DIB-443 Sidekick Passive Direct Boxis a passive direct injection transformer that changes guitar or bass signal to a low-impedance signal appropriate for sending down the snake to the house (or studio) mixing console's XLR inputs. An "INST/SPKR" switch, when placed in the SPKR position allows an amplifier's extension speaker output to drive the line, thus preserving the original amp sound. A Ground Lift switch breaks ground to help trouble-shoot and terminate 60Hz "ground-loop" hum.