Specification: Item Type: Helmet Headphones Material: ABS BT Version: 5.0 Frequency: 2.402GHz-2.480GHz BT Distance: 10m-20m / 10.9-22.0yd (Depending on the Environment Around the Device Such As Obstacles) Microphone Transmission Distance: ≤1m Built in Battery: 3.7V / 450mAh x 2 Li ion Batteries (Ship with Inbuilt Battery) Playing Time: ≤16 Hours Charging Voltage: 5V Charging Time: About 3 Hours Standby Time: ≤720 Hours When you press the power button for 3 seconds, the device turns on with a"power on"tone. BT pairing: 1. Press and hold the power button for 3s, you will hear the voice prompt"power on". Open the BT phone, search the pairing name "You will hear the voice prompt"Connected"and the BT is successfully connected. (If your cell phone or other BT device version is BT2.0, you need to input the pairing password"0000") 2. Connecting two cell phones When one phone is paired with the headset, turn off the BT for that phone, then pair the second phone with the headset, and then turn on the BT for the first phone again. 4. Automatic search When the phone BT is disconnected from the headset (voice prompt Disconnected), it will enter the automatic search pairing mode. 6. Switch songs/sound increase/decrease Short press"‑"to switch to the previous song. Press and hold to decrease the volume. Press"+"briefly to switch to the the following song. Press and hold to make the sound louder, and there is a beep when the volume is maximum Package List: 1 x Helmet Headphones 1 x Micro USB Charging Cable 1 x User Manual