I'm a GP, and like some other reviewers, I remember when these cost £500. This works as well as others I have used - perhaps a little slower than some, but fine. I'll be interested to see how long the batteries last as it has an LED display and more expensive devices use LCDs. (But all sats meters use LEDs for the actual measuring). Durability - who knows? But I've used much more expensive devices that fell apart in a couple of years. At this price you can't go wrong, and I'm buying one for every clinical room at our large practice.