iRiverOn Iriver On Hrm Earbuds 14IFM001-CMWE02 Accurately measures heart rate & provides voice guideance to users through Valencells patented PerformTek biometric technology Compatible with iOS or Android Smartphones which calculates heart rate, distance, time, and calories burned Listen to music, make/receive calls, and share exercise results with friends on Facebook Measures maximum oxygen uptake (VO2 MAX) and provides real time data and feedback of your exercises 2013 Red Dot Design Award winner for ergonomic product design