These are new in stock... high quality sound filters and durability
Brand Name: Lenovo Model Number: QT81 BT Version: BT 5.0 Transmitting Distance: 10m/33ft (no obstacle) Drive Unit: 13mm Frequency Range: 20-20KHz Sensitivity: 98±3dB Impedance: 32Ω Charging Box Capacity: 3.7V 1200mAh Earphone Battery Capacity: 2 * 3.7V 40mAh Music Play Time: about 5 hours (depends on music volume) Waterproof: IPX4