JBL Charge 4. RMS rated power 30 W. Frequency range 60 - 20000 Hz. Signal-to-Noise Ratio (SNR) 80 dB. Connectivity technology Wired & Wireless. Frequency range 2.402 - 2.48 GHz. Bluetooth profiles A2DP.AVRCP. Product colour Grey. Housing material Fabric.Rubber. Volume control Digital. Recommended usage Mobile phone / Smartphone. Power source type Battery. Battery type Built-in battery. Battery technology Lithium-Ion (Li-Ion)