Wireless audio transfer. The transmitter connects to the headphone or RCA output on the TV, DVD, stereo, computer, etc. Auto frequency search for easy connection. Switch for extra bass amplification. The transmitter is powered by the enclosed mains adaptor. Speakers (IPX3) operated by 6 x AA/LR6 batteries per speaker (sold separately) or by the included mains adaptor. Both mains adaptors are for indoor use only. Max range: 30 m line-of-sight. Speaker diam: 15 cm. Height: 20 cm.