Bergmann Technik BT-1050 Bluetooth Stüdyo Kulaklık ∙ Bluetooth chipset: CSR 8635, version 4.0 Bluetooth profiles: HSP, HFP, A2DP and AVRCP Noise Reduction: up to 20dB between 50 to500Hz Battery: Lithium battery 250mAh Driver unit: 40mm Neodymium ∙ Sensitivity: 100dB±3dB Weight: 210g ∙ Frequency: 20-20KHz ∙ Impedance: 32Ω Working time: 8 hours at medium volume ∙ Color: Black