BSS AR-133 | Active Direct Injection Box The unit is housed in a rugged aluminium extrusion case, with robust polyurethane end-cheeks which give the AR-133 a very distinctive look The arched case allows cables to run back underneath the unit from the end for neat cable management The unit is housed in a rugged aluminium extrusion case, with robust polyurethane end-cheeks which give the AR-133 a very distinctive look Input attenuation is 0, -20 or -40dB, making the box suitable for instrument, line or amplifier levels on inputs Input attenuation is 0, -20 or -40dB, making the box suitable for instrument, line or amplifier levels on inputs. On the output side, a ground-lift switch is provided for quick solutions to ground-loop problems.