The tanita rd 901 bluetooth body composition monitor is a wireless machine made for use at home that transmits data via bluetooth 40 so you can analyse it on an iphone via the health planet app or online readings are very accurate as the monitor uses the latest medical grade dual frequency bia technology to measure 10 different units from weight and bmi to muscles mass and metabolic age your data is clearly displayed on the screen and it has some other great features such as memory for 4 user