A 2.1-channel monitor system for electronic drums. Bought new in 2012Not dual voltage and I'm moving to a 120V country Satellite speakers: 20W, with 4" woofer, 2" midrange, and 1" tweeterSubwoofer: 40W, with 10" woofer The Yamaha MS40DR Electronic Drum Monitor consists of left and right satellite speakers that may be attached to a rack, plus a subwoofer with a bass-reflex amp. These speakers enable you to experience intensely realistic stereo sound that will make you feel like you are performing on an acoustic drum set.  A line out connector may be used to connect to a mix input connector, a recorder, or a mixer. Also features mix input and headphone jacks. Controls include knobs for main volume, woofer, treble, and mix in. Outstanding for monitoring in the home or at live performances and recording sessions. The system may be attached to any DTX drums drum rack.