LENYES Air 301 ● Wireless version: V5.3 ● Bluetooth protocol supported: A2DP1.3/AVCTP1.4/AVDTP1.3/AVRCP1.5/HFP1.5/SPP1.0/SMP/L2CAP4.2 ● Working frequency: 2.402GHz-2.480GHz ● Bluetooth effective distance: ≥10m ● Speaker power: 2mW ● Audio signal-to-noise ratio: ≥90dB ● Frequency response: 20Hz~20KHz ● Built-in battery: 3.7V, 20mAh ● Music playback times: 3-3.5 hours (70% volume) ● Talk time: roughly 2.5 hours (70% volume) ● Headphone standby time: approximately 67 hours ● Charging time: approximately 2 hours ● The charging case has a standby time of approximately 400 hours