Features:
1. Compatible with most devices that may utilize headphones.
2. LED power indicator for power on and charging.
3. 360-degree sound field intergrates a cone design with a custom-built speaker to project sound in all directions.
4. With 1.4 subwoofer, the vacuum base offers deep and rich sound with HI-FI result.
5. Pioneering patented technology: extendable resonance of the bass box technology enables stronger effect.
6. New concept integrative portable mini speaker, with small bulk can play on the center of the palm.
7. Embedded type lithium batteries, can use USB or power adapter for charging.
8. More convenient and user-friendly, cost-saving pruphase batteries.
9. Built in, rechargeable lithium battery each charge can last for 3 - 5 hours.
 
More details about the speaker: 
Type: Speaker Amplifier
Output: 2.4w
Rating Power: 2.2w
Size: 50mm (W) x 50mm (L) x 35mm (H)/1.97'' (W) x 1.97''(L) x 1.38''(W) (Approx.)
Socket Size: 3.5mm
Speaker: 36mm Micro Speaker, 4Ohm
Frequency Response: 200Hz - 20k (Hz)
Singal-to-noise: >89db