Works good on power supply and/or battery. I was dissapointed it uses four AAA batteries and not the standard AA size used by other companies. I highly suggest using the supplied 6V powerpack for regular in home use to save the batteries. The wide range cuff is definitely wide range. I can not imagine an arm too small or too big to exceed the cuff adjustability. The cuff appears to be standard quality. I was surprised the machine has a soft screeen and not hard plastic like other machines. It does not appear to be any future issue with usage or life of the monitor. I am happy with my purchase.