"Portronics are happy to launch""PureSound Plus""- a rechargeable Bluetooth speaker with extraordinary clarity of sound and sleek stylish looks. It has 3 x 2W Speakers with great amplifiers offer a powerful and clear sound output at all frequencies and tones - bass, mid-range and treble. Humans can hear sound frequencies from about 20Hz to 20kHz. The basic frequency range of the bass is 40Hz-400Hz and can go up to 4000Hz for bass harmonics. A mid-range speaker is a loudspeaker driver that reproduces sound in the frequency range from 250 to 2000 Hz. Treble refers to tones whose frequency from 2.048 kHz-16 kHz- range is at the higher end of human hearing. The powerful industry-leading size of 2200mAh lithium Ion battery can play music for more than 5-6 hours on a single recharge. "