LENYES Air 301 ● Wireless version: V5.3 ● Support Bluetooth protocol: A2DP1.3/AVCTP1.4 /AVDTP1.3/AVRCP1.5/HFP1.5/SPP1.0/SMP/L2CAP4.2 ● Working frequency: 2.402GHz-2.480GHz ● Receiving sensitivity: -93dBm ● Bluetooth effective distance: ≥10m ● Speaker power: 2mW ● Audio signal-to-noise ratio: ≥90dB ● Frequency response: 20Hz~20KHz ● Built-in battery: 3.7V, 20mAh ● Music duration: 3-3.5 hours (70% volume) ● Talk time: approximately 2.5 hours (70% volume) ● Standby time: headphone about 67 hours ● The charging case has a standby time of approximately 400 hours ● Charging time: about 2 hours