BS633AT (BS633A Wall Speaker with Built-in Attenuator)The BS 633AT is wall mount speaker made of ABS resin and can be hooked or mounted directly on the wall. The push in type input terminal makes cable connections easy and allows bridge wiring. The input impedance can be easily changed by changing the tap position of the transformer from the rear side of the speaker. The BS 633AT has a built in attenuator and can be connected to a 2 wire and 3 wire systems. Product Features Compact and unobtrusive design