Panasonic portable wireless speaker system SC-MC20-R (red) Speaker: Full range 3.6cm  2 cone type Connection terminals: headphone output stereo 3.5mm jack (applies impedance 32 ~ 64) Power supply: built-in rechargeable battery DC 3.7V (1400mAh) 5.2Wh (Li-ion battery) / AC adapter (VSK0771) / Input: AC100V ~ 240V (50 / 60Hz) Dimensions: Speaker: width 104mm  height 45mm  depth 104mm / wireless transmission unit: width 44mm  height 69mm  depth 16mm / mass :( speaker) about 191g / (wireless transmission section) about 25g Japanese manual download site URL:http://panasonic.jp/compo/p-db/SC-MC20-R_manualdl.html