Its time to really break free from your headphone cables! The Phiaton PS 20 BT Bluetooth Stereo Headset is a stylish and lightweight personal calling and music listening solution that combines the total freedom and flexibility of cable-free and hands-free Bluetooth technology with a dramatically enhanced audio experience. Thanks to the built-in Bluetooth v3.0 technology, users can easily answer phone calls without having to remove their earphones - and with the special Echo-Off Noise reduction technology, background noise is virtually eliminated while you're on a call. For total flexibility - and to make sure you never miss a call-the PS 20 BTs provide a calling / music playing time of 6 hours and 250 hours of standby. Musicality and overall audio quality is a top priority in all Phiaton products, and the PS 20 BTs' powerful 14.3mm drivers produce pure and accurate sound. Most importantly, the unique half in-ear design of the earphones allows them to be worn just outside the ear canal for a comfortable fit and hours of listening enjoyment anywhere, anytime. PS 20 BT Bluetooth Controller Specifications: Communication Network: Bluetooth standard Ver.3.0; Operating Range: Within 10m; Bluetooth Profile: Support A2DP, AVRCP, HFP, HSP; Battery: lithium polymer DC3.7V / 150mA; Microphone Frequency Response : 10 - 4,000Hz; Microphone Sensitivity: -40 dB; Dimensions: 51 x 30 x 17( mm); Weight: 16 g. PS 20 BT Earphones Specifications: Type: Dynamic; Driver Diameter: 14.3 mm; Sensitivity: 110 dB/mW; Frequency Response: 15 - 22,000Hz; Impedance: 32 ohms.