Gembird BTHS-004. Bluetooth version: 2.0+EDR. Acoustic system: clip-on. Microphone frequency: 1 - 2 Hz. Battery technology: Lithium Polymer (LiPo), Battery capacity: 120 mAh, Talk time: 6.5 h. Dimensions (WxDxH): 70 x 21 x 12 mm, Weight: 12 g