The Weekend Brewer 6-pack 16 gram 3/8" Threaded Disposable CO2 Cartridges (6, 16g)

Have no problem with the product itself. They thread easy, but when changing, wait for the regulator (if you're using a growler keeper like I am) warms up, or it won't thread easy; let it warm up and expand a bit.What keeps this from being a 5 is that for less than the Prime price in the comparison picture you can get twice as many cartridges direct from the supplier. Sure it takes longer, but the quicker Prime deliver (and for what we pay now annually) is NOT worth THAT much.C'mon Amazon! You all are smarter than that!

works as expected

They are co2 cartridges. They work.