UNIKARO Premium lithium battery, specially designed for W-KING D10 Bluetooth speakers, uses high-quality Li-ion cells with 7.4 V and 8000 mAh capacity for long-lasting power – so your music party or outdoor entertainment won't be interrupted. The battery is safe, reliable, and easy to install, faithfully replacing the standard battery and restoring your speaker to full power so you can enjoy stable, powerful sound.