Sony SRSM50/BLK Compact, Stylish, Transportable Speaker (Black) (Discontinued by Manufacturer) Powerful Sound Reproduction Bass Reflex, Full Range Type Speaker System 39Mm Driver Unit Powerful sound reproduction Bass reflex, full range type speaker system Total output power: 5W (2.5W + 2.5W) Stable bass sound with clear vocal listening Built in battery compartment for enjoying music any time, any place (AAA x3 optional)