This Certified Refurbished product is tested and certified by the manufacturer or by a third-party refurbisher to look & work like new, with limited to no signs of wear. The refurbishing process includes functionality testing, inspection, reconditioning and repackaging. The product ships with all relevant accessories, a minimum 90-day warranty & may arrive in a generic white or brown box.Only select sellers who maintain a high performance bar may offer Certified Refurbished products on Amazon. Activity tracking steps, elevation, distance and calories burned. Instant Heart Rate measurement. Sleep quality monitoring. Please make sure that your mobile device is compatible with the Withings Pulse(TM) Ox. Please charge it for at least two hours. After charging it, press the button for 15 seconds. At this point, it can take up to a minute for your Withings Pulse(TM) Ox to start. iPhone (3GS or later), iPad (except the original iPad - App not iPad optimized) or iPod touch (4th generation or later), with iOS 6.0 or later and Internet access (mobile data or Wi-Fi). Bluetooth-enabled Android smartphone or tablet with Android 2.3.3 or later, Internet access (mobile data or Wi-Fi) The product may not work if exposed to water