Seems very accurate. Comes with everything included such as good instructions, an adjustable armband, a/c adapter, soft case and computer software. This is unlike many of its competitors. Caters for three separate users each with 40 memories and also monitors irregular heartbeat. I find the 4 AA batteries last for ages so I haven't needed to use the a/c adapter yet. I bought it for $60 on sale which was great value but I'm not sure if it is still being manufactured.