I was wondering about that.
I was thinking that with such a simple device, a cheap one might be good enough especially when you probably only use it once every year or two? (hopefully)
I have Schrader valves, so that should help.
I still have to put my Flat Out in my tires, so I'll use the CO2 inflator to reinflate the tires to see how it works and if it's a piece of crap.
It did say in the description that it fits both Schrader and Presta valves.
I picked the one with a twist valve thinking it might be more reliable.
It also said that you are supposed to use it up within 24 hours of piercing the CO2 cartridge (because it leaks out eventually) and you are supposed to let all the CO2 out of your tire when you get home and fill it back up with air.