Bluetooth speaker makes you free from troubles of cables, very easy to use Special bulldog design makes your speaker different to others With transmission distance is up to 10meters Support playing audio files in MP3 and WMA format through TF card and U disk With FM radio function, built-in 87.5-108MHz FM digital radio module, can automatically store 50 radio stations Built-in rechargeable 800 mAh battery, it could last a whole day when you listen to music 52mm speaker unit, the sound is clear, loud and undistorted, bring excellent stereo music Specification: Specifications: Battery : 500MAH 18650 Bluetooth chip: Jerry Bluetooth version: 4.2 Charging time: 4 hours Frequency: 50-20KHZ Audio frequency: 87.5-108MHz Speaker parameters: 52MM full frequency magnetic horn Output power: 3W Signal to noise ratio: 80db Communication distance: 10m