Helium Digital HDBT-750 Bluetooth headphones w/microphone Features of the HDBT-750 are as follows; Bluetooth V2.0, AVRCP & A2DP Bluetooth Profile Support Automatic Music/ Phone switching, Headphone Volume adjustment, Built In Echo Elimination & Noise Suppression, Ultra Lightweight- Only 50 grams, Rechargeable Lithium Ion Battery - 6.5 hours Battery Life, Working distance approximately 15 meters