Home Use Soda Refill Bottle CO2 Cylinder Cartridges, Adapter Refills Connector Kit CGA320 to TR21-4, Thread Set Replacement Accessories for Soda Machine Tank, Gold

Filled up my CO2 on the first go.Helpful tip-- DO NOT USE the RELEASE VALVE.The very first time I used it, the o-ring blew.You will know if it blows because the next time you go to fill a bottle there will be slight leak because the release valve won't have a closed seal.They only give you four extras, but if it happened on the first time I'm just not going to use it. There's not much pressure in the fitting space between the soda cylinder and the tank.Otherwise it works as expected.I had one with a hose and it was just ridiculous with the wasting of the CO2. You don't need a gauge. I would have been happy to stick with the hose one however it imparted a funny taste into my CO2 so this works great.I filled super slowly on the first go but probably too slowly because I was sitting there for like 8 minutes and it still was going. I went to video they had on the little instruction booklet just to confirm.I think it's weird how and none of the instructions say to close down the release valve before you start filling in case someone didn't know- for someone who's never done this it is helpful to know that the release valve should be closed before you fill.Anyways you don't even need it Don't use it seriously.Also like another reviewer said I stacked the clear plastic o-rings together on the SodaStream side because it just fit better and it works.

Works well, but the small O rings break easily. The package needs to have more O rings included. Most important to fill the canisters SLOWLY.

Had previously bought: https://www.amazon.com/gp/product/B089GXJ3T3 ... this is so much simpler (less clumsy), and the hoses on the other side quickly deteriorate and leak... this is much simpler and less expensive... EXCEPT FOR THE BLEED SCREW. It was leaking, so I tightened it, and it broke off. Don't use the bleed screw to release pressure, just unscrew the sodastream bottle (carefully). There's not a lot of trapped gas to release in this design.I used both sodastream bottles with refillable and unrefillable end caps... from my previous experience, I knew "get as much as you can into the unrefillable style, and be happy with what you get".I did see in one one video: freeze the empty bottle prior to refilling. Good idea.Another video said this comes without a pin needed to fill the bottle, and they used a screwdriver on the end... with no explanation. I'm not following this, nor know what the pin that not's included is referring to., The bottles seemed to fill correctly anyway.

EDIT:I left the positive review below a few months ago, but now have to revise downward for one simple reason. The metal used on the relief valve thumbscrew is utter garbage. After only a few months of use, the head completely sheared off while hand tightening this valve, leaving the unit useless. Looking at the broken off edges, it appears to be cast form extremely low grade, weak, pot metal. A pity, too, because the brass connector itself appears quire well made.Dropping this to one star and recommending you look somewhere else, as this unit just won't hold up.ORIGINAL REVIEW:I picked up one of these to fill classic Soda Stream CO2 tubes from a 10lb tube I use for a kegerator setup, and so far it has worked out quite well. It's machined from solid brass and is quite effective if you know what you are doing. I'd give this five stars, but the o ring on the relief valve was installed incorrectly, so it leaked out of the box. Luckily, it included multiple replacement O rings, so it was an easy fix.Some use tips:1. Your Soda Stream tube MUST be at freezing temperatures in order to fill properly. This is because the pressure CO2 is liquid and will gassify as it hits the warm tube, preventing a full fill. I put mine on ice about an hour before filling for best results.2. Point your source cylinder DOWNWARD while filling, which will allow the CO2 to flow into the Soda Stream tube.3. Open the valve on your source canister slowly, until you hear the gas flowing. The Soda Stream tube has a lockout on the pin that will prevent the flow if you open the valve too quickly.4. After you've filled your Soda Stream tube, close the valve on your source cylinder, and turn the relief valve on the coupler to vent excess gas. This will make it a lot easier to remove the coupler.5. Since this is an unregulated coupler, this will fill until the pressure on each side is equalized. Therefore, your best fills will come when your source tube is full. If you are filling from an emptier cylinder, your Soda Stream tube will not fill fully.