Neck Behind design features an around-the-neck wearing style with a body-contoured fit. This headset is light yet powerful enough to provide up to 5 hours of music listening time and 12 hours of talk time on a single charge. It offers top-rate sound with advanced audio features, enhanced bass response, HD Voice, making for an incredible listening experience with full, rich, authentic sound for music and crystal-clear voice calls. Unique memory flex neck strap for weightless comfort Advanced Multi point allows the Speed HSB-730 to connect to two devices simultaneously and lets users switch from listening to music to phone operation with minimal effort. Features: Unique ring-necked design, opening up a new era of bluetooth, Ultralight elastic memory material, easy to carry, Vibrate to remind you not to miss any incoming calls, High-fidelity stereo audio earphones enjoy entertainment, Intelligent noise reduction, clearer calls, Long standby, long call. Compatible with standard bluetooth-enabled mobile phone, media devices. Answer/end/reject a call. Last number redial, voice dialing, transfer a call, call waiting. Specifications:- Bluetooth version: V4.0, Battery: Battery 3.7V/180mAh, Standby time/Talk time: Up to 30 hours/ up to 1 hour, Music play time: Up to 5 hours, Charging time: <2 hours.