I was surprised how small the tire inflator is. This is a size 10/11 men's ankle boot. Well built, although it hums when you turn it on. My previous Revain tire inflator was a Breezz, it made a rattling noise and only triggered 4 or 5 times. Can't comment on the durability of this unit but it hums like a well made machine and had no trouble inflating my tires (215/70/17). 5 stars for accuracy refer to the digital pump sensor. I can't remember what the instructions say (in the trunk of my car), but my tire gauge indicated that shutting off the pump at Β½ lb over my target tire was as accurate as I could confirm with a tire gauge. A bag of ditties is good too. Thank you Astro!