DSP / Foldable design / Easy switching between call and music modes / Up to 7.5 hours music & up to 9 hours talk time / 34mm speakers # Bluetooth Stereo Headset Headphones by Nokia, not only plays music, but also takes phone calls, with its 34mm neodymium speakers and its 20 Hz to 20 KHz frequency response. The BH-504 features advanced Digital signal Processing (DSP) and easy switching between music and talk modes, so you can enjoy your music while also taking business phone calls with clarity and ease. Its foldable design makes it perfect for Storage in your briefcase during business meetings. Advanced digital signal processing (DSP) # Designated keys to control your calls and music # Foldable design for easy mobility # Easy switching between call and music modes # Operating time: up to 7.5 hours music & up to 9 hours talk time # Charging time: up to 1 hour # Compatible Nokia chargers: Nokia Compact Travel Charger AC-5 # Standby time: up to 90 hours # Total harmonic distortion: 0.1% # Frequency response: from 20 Hz to 20 kHz # 34mm neodymium speakers # Bluetooth versions: 2.1 with enhanced Data rate (EDR) # Bluetooth profiles: # Hands free profile (HFP) 1.5 # Headset profile (HSP) 1.1 # Advanced Audio Distribution Profile (A2DP) 1.0 # Audio Video Remote Control Profile (AVRCP) 1.0 # Operating keys: # Multifunction key (power on/off, pairing, answer/end, and reset # Play/Pause/Resume/Stop # Next Track/Forward # Previous Track/Rewind # Volume Up # Volume Down # Unit Dimensions: 6.69" x 5.65" x 1.92", Weight: 3.81 lbs. # Compatible with phones and devices supporting Bluetooth Specification 2.1 + EDR and higher, Hands free Profile, Headset Profile and A2DP/AVRCP profiles