USAMS 'second-generation bluetooth headset, with increased performance, standby and usage time, and bluetooth 5.0 technology, provides services from premium brands at a very affordable price. The F10 earphone holder dock has a built-in 1500 maAh battery, so you can charge the earphones at any time without the need to connect them separately with a cable to the AC adapter. Charging in the case starts immediately and charges the headphone heads in about 15-20 minutes. Thanks to the increased performance, the headphone battery with 40mAh capacity already provides 4 hours of wireless music listening and more than 360 hours of standby time. The USAMS BHUL02 already provides stereo sound when using the headset feature, and bluetooth 5.0 is much more efficient, capable of transferring eight times as much data twice as fast. In addition, BT 5.0 technology has significantly increased bluetooth range. The 400 mAh battery in the charging case quickly charges the headset after insertion. Once you have turned on the bluetooth function on your mobile device and a bluetooth connection is established with your phone, you also need to pair the headset heads with each other by pressing the button on it. In addition to crystal clear sound quality, the headset also has a headset function. You can activate call answering by pressing the key on the right headset.