BSS AR-133 mono active DI boxIntroducing the BSS AR 133 mono active DI box The AR 133 unit is a mono active direct box that includes phantom power and battery supplies as standard. Should the phantom power from the console fail or be accidentally switched off, the AR 133 automatically switches over to the internal 9V battery providing uninterrupted use. It's housed in a rugged aluminium extrusion case, with robust polyurethane end cheeks that give it a very distinctive look. It