Model: Aukey EP-T25 Technology: BT 5, A2DP, AVRCP, HFP, HSP, AAC Driver (each channel): 1 x 6mm / 0.24” speaker driver Sensitivity: 90 ±3dB SPL (at 1kHz/1mW) Frequency Range: 20Hz – 20kHz Impedance: 16 ohm ±15% Microphone Type: MEMS (microphone chip) Microphone Sensitivity: -38dB ±1dB (at 1kHz) Frequency Range Microphone: 100Hz – 10kHz Charging Time: 1 Hour Battery Life: Up to 5 hours Battery Type: Li-polymer (2 x 40mAh) Operating Range:10m / 33ft IP Rating: IPX5 Weight: 7g (pair)