Gnc has been the leader in helping american’s live well for more than 75 years. live well knowing your heart is in shape with the digital talking wrist blood pressure monitor. the large lcd screen is 50 x 44 mm and has a time and date stamp. the body movement indicator gives an average calculation using the last 3 measurements to detect irregular heart beats. automatic inflate and deflate makes it easier to use and it even measures while it inflates so you don"t have to wear it as long. it"s powered by 2 aa size alkaline batteries and has an automatic power-off function to save energy.