BT-X21

Function: Bluetooth，phone call，tf Card, AUX
Water proof, class 4
material ABS + SILICON 
chipset:BK 2.1+EDR; support 3.0 version 2.4G   
distance 10meter   
Speaker: Ø40mm，4Ω/3W 16 double inner magnetic core, 
4Ω/3W vibration gun-side-film   
Amplifier 3W   
Battery  300MA polymer battery   
working time: 2-4H   
Product size mm;