Suit for Iphone 4S or Above Iphone Series, also suit for Android Cellphone support Bluetooth 4.0 Use High Quality CR2032 Battery, Lower Consumption, continue work 10 months. Comfortable design will not lead you feel a sense of pressure. Real time Heart Rate Monitor. Lower Consumption. Partner with IPHONE 4S and Above Systems. Free App Download on iTunes Unlimited Save History Data. Heart Rate Curve Drawing. Mapping the heart rate curve.