I think I should have read the product description a little better but the adapter doesn't seem to be suitable for reading pressure gauges, just for inflating the Shrader air pump. It seems strange that you received a presta valve inflation adapter but not a presta valve reading accessory. Also, it comes with very minimal instructions. For these reasons I lowered my rating by one star. Also, it's really well made, works great with Shrader valves, and the storage box for it and accessories is nice.