Rolls MX44 PRO 4-Channel Stereo MixerMX44 Pro 4 Channel Stereo Mixer. This unit is designed to mix up to four stereo line level signals such as smart phones, instruments, CD players, DVD players, MP3 players, laptop computers, etc. to a single stereo output. Features: Four stereo inputs to one stereo output Stereo RCA and 1 8" TRS Stereo high impedance inputs Stereo RCA and 1 8" TRS Stereo high impedance output Battery or AC operation