iKross Bluetooth 4.0 Stereo Headphone Headset with Built-In Microphone - Black Red iKross Bluetooth 4.0 feature: 8 times the bandwidth over the 2.1 standard producing crystal-clear sound quality. A2DP Bluetooth profile allows for ultra-high definition media playback. Allows switching between music and phone calls with bluetooth enabled phones. Bluetooth Version 4.0, Bluetooth Profiles: HSP, HFP, A2DP & AVRCP, Playback Time:10 Hours, Talk time: 10 hours, Stand by: 800 hours. Integrated microphone, and A2DP Bluetooth 4.0, supports hands-free calling and lets you control your music and phone calls from up to 30 feet away from your phone. Can be Connected with two Bluetooth devices at the same time.