1. Special voice prompt, calling answer, voice notice phone number. 2. Military technology shell, alloy steel, antiwear material 3. Exquisite design, easy cooperating. 4. Pneumatic pressure cone technology, neodymium iron boron speaker, perfect quality sound 5. Dual power, built in 3.7v 500mah lithium battery, external dock 3.7v 1020mah battery, it can be used as power bank. 6. Bluetooth v2.1+edr 7. Using for meeting, travelling, car kit, children teaching. Channels : 2 (2.0) Special feature : wireless, portable, mini Special function: with phone function Type:bluetooth speaker Color: red , silver , black, green, metal Use for : iphone, ipad, cellphone Connect by : bluetooth / aux cable 2.5mm jack Bluetooth: v2.1+edr Power : 1.5w Frequence : 65hz-20khz Distortion factor : thd86db Builit in battery : 3.7v 500mah External dock battery:3.7v 1020mah