iKross Portable Bluetooth Wireless Handsfree Microphone Headset for Nokia Lumia 830, 1320, 610, 635, Icon (929), 1520, 2520, 1020, 520, 620, 925, 928, 521, 822, 810, 920, 820 Answer / End / Reject call, Comes with On/Off button. Volumn control Bluetooth version: 3.0, Supported profiles: HSP, HFP, A2DP. Talk time: up to 4 hours. Standby time: up to 125 hours. SIZE: 1.22 x 0.63 x 0.43 inches (31 x 16 x 11mm). Compatible with Most Bluetooth Enable Cell Phone, Smartphone Tablet