BT048NC Over-ear ANC and ENC Noise Reduction Wireless Headphones 1. Bluetooth 5.4 chip for a more stable connection 2. Active Noise Cancellation (ANC) accurately calculates ambient noise and intelligently cancels it with reverse sound waves, achieving a noise reduction depth of -43dB 3. ENC for call noise cancellation for clearer voice calls 4. HiFi-level audio quality experience, built-in powerful 40mm driver unit, dynamic stereo sound with high and low levels 5. Ergonomic design with retractable adjustment to fit various head shapes 6. Dual connection with one device, one pair of headphones can be connected to two devices simultaneously 7. Ultra-long battery life, with a charging time of approximately 3 hours and a battery life of up to 55 hours. When the headphones run out of power, you can continue to enjoy excellent high-resolution audio using the included audio cable. Specifications 1. Bluetooth protocol: 5.4 2. Transmission range: 10 meters 3. Material: ABS 4. Battery size: 3.7V, 500mAh 5. Playtime: 55 hours 6. Speaker size: 40mm 7. Battery life: 8 hours Package List 1. Bluetooth Headset x 1 2. Charging Cable x 1 3. Audio Cable x 1 4. User Manual x 1