Features: 1) Suitable for MP3, MP4, CD, notebook, PC, PDA, PSP, mobile phone and other digital products with audio frequency output 2) With unique anti-traditional design, the power amplifier, batteries and double loudspeakers are all collected in the egg-sized sound box body 3) The originally patented retractable resonator has solved a difficult problem of too small resonator of mini sound box 4) The dimension limit of sound boxes has been decreased to the minimum Product material: ABS Painting:ordinary paint HIFI IC:APA3010KA Loudspeaker impedance:antimagnetic(4Ohm)36MM*2W Loudspeaker output:2.35W rating power:1.85W frequency response:100HZ-22KHZ Singnal-to-Noise:≥85db Distortion:≤0.5% input:DC 5V , USB; input :AAA 3PCS keeping display time:3hours ~8hours(MP3 volume 20mv~ 31mv) Net Weight:58g(excluded batteries) Suitable ambient:(length*width*highness) 6.1cm*5cm*3.5cm