This is probably the best price you’ll find on ISI CO2 chargers. While you might find cheaper brands, you know these will all work. If you use many chargers, this is a solid price.Works well in ISI soda siphonsA big problem with soda cartridges in my experience is getting ones that leave a machine oil taste in your drink. The iSi Golds cost a little more but never do that. Recommend.Makes easy soda water to add to our drinks. Perfect for home bars.Takes a couple tries to get it right, but be patient if you’re struggling. I probably wasted 5-6 before I figured it out so I never used it. But now I always get it right, no more waste, and I love my iSi Soda makes thing.The tricks I’ve found that work are using cold water- I actually use a cocktail shaker to chill the water. Fill it up until it overflows a bit. Tighten the top pretty good before you put the charger in, but you don’t have to get crazy Hulk on it. Put the charger thing in the cap thing before you connect the charger. Shake it up really good before you pour your water every time and keep it in the fridge. The colder the water, the better it works.I buy tonic syrup for cocktails and this is perfect for a not too sweet G&TThey work well for what they are, CO2 cartridges. Don’t know if there is such a thing as food-quality CO2 as I use these to make club soda. I pay the premium price until someone shows me the cheap pellet gun CO2 cartridges are the same.Update: Someone once said if you are paying $3 for your bottle of SmartWater, it’s not working. Well, I’m still paying $.93 per cartridge for carbon dioxide. I’m not happy about it. Each cartridge makes 1-qt of fizz water, about 4 8-oz glasses. I think our daughter-in-law has the right idea: she has a Soda Stream machine. Much more efficient. And, the large cartridges can be recycled.Perfect for our ISI siphon. Right amount of gas. Just a little pricey, but are of excellent quality.Despite these Isi carbon dioxide cartridges are expensive I would never buy another product for my ISI Seltz water siphon. Before making your choice I recommend you read other reviewers points of view; in effect there are many brands on the market, but unfortunately despite their product look the same and seem to contain the same amount of gas, it turns out that some are better than others. I would avoid the ones from China as Ihave read many complains about the quality and quantity of gas there is inside. Having to use 2 cartridges instead of one to fill a 1 liter soda siphon is exaggerated according to me. It seems that at least the ISI cartridges are still filled in Europe and that the law and company values are strict enough to maintain a certain quality level. As a student, I wish there was a similar product made in the USA with the same quality and a more attractive price.I have bought these for some years. .The latest batch were labled extra fizz and do not fit a sparklets inserton tool. Hence a complete waste ofmoney.The profile of the new bulbs is different from the old one.Soda water is not as fizzy as shop bought. I am not sure if it is the gas or the way I make it. When possible still prefer the shop bought soda water.Since my last delivery the shape of the capsules has changed. This means that they do not fit into the device which is used to screw the capsule onto the siphon to recharge it. I have three different versions of the charging device but the capsules do not fit any of them without modification.The cartridges didn't give a very fizzy drink, and the drink didn't stay fizzy for very long!Good