Battery-operated portable 50-watt Multimedia Stereo Amplifier with 3 mic inputs, line in with separate volume & tone controls; line out. The amp works with most microphones including condenser dynamic and wireless. The condenser (electret) input includes phantom power. All 3 mic inputs can be used simultaneously. Tape record your mixed multimedia presentation as it is happening Or provide a mixed output to the room's built-in sound system that you control. Connect (with optional Y-jacks) up to four speakers. Power with 10 alkaline D-cell batteries. AC Adapter/Recharger or rechargeable NiCad Battery Pack, also available. 8-1/2"W x 8-1/2"D x 3-1/2"H overall.