SONY WI-XB400 Extra Bass Wireless Stereo Headset Bluetooth Headset (Black, In the Ear). Wireless Extra Basss Neckband Headphones for casual and daily usage. Frequency Response (Bluetooth Communication) 20 Hz?20,000 Hz (44.1 kHz Sampling). If the size of the earbud tips does not match the size of your ear canals or the headset is not worn properly in your ears, you may not obtain the correct sound qualities or call performance. Change the earbud tips to ones that fit more snugly in your ears. Battery Life Up to 15 Hours of battery life Quick charge in 10mins for 60mins playback. Magnetic housing for tangle-free listening. Headphones with Mic In-Built Mic for Hands free calling with HD voice. Light Weight Portable headphones with ultra lightweight at 21g design. Voice assistant Google Assistant for voice access to music, information and more. Activate with a simple touch. Colour Options 2 classic colours to blend into your outfit. Driver Unit 12mm driver unit offers clear sound quality.