Two 26 inch passive speakers paired with a matching amplifier that accepts a 12V power supply. Key benefits Clear, room filling sound from large passive speakers when driven by an external amplifier. Simple tone control with bass and treble adjustments plus overall volume for quick, on the fly tuning. Broad device compatibility: can connect to mobile phones, computers, MP3 players, and set boxes. System details Speakers: 2 x 26 inch passive speakers Amplifier: supports 12V power supply Power connector: 55 x 2.1 mm plug Controls on amplifier: power switch, bass adjustment, volume adjustment, treble adjustment Connections: suitable for standard consumer audio sources from mobile devices to media players and set boxes Use scenarios Home entertainment setup: connect a media player or PC for movies, music, and games with adjustable tone. Small office or classroom presentation: reliable audio playback with simple volume and tone control for clear speaking and ambient music. Small venue or event setup: scalable by using a compatible external amplifier to achieve higher volume while maintaining control over tone. Notes This is a passive speaker system and requires an external amplifier to operate. The amplifier uses a 12V DC power supply. The amplifier power input uses a 55 x 2.1 mm plug. Specifications Speaker configuration: 2 x 26 inch passive Amplifier power input: 12V Power plug: 55 x 2.1 mm Controls: power, bass, volume, treble Compatibility: supports connection to mobile phones, computers, MP3 players, and set boxes