Stainless Steel Carbonation Cap, Ball Lock Keg Post 5/16'' Beer Line Nipple Barb & CO2 Coupling for Soda Drink, PET Bottles Counter Pressure Bottle Filling Cap with Gasket & O-Rings

I'm using these for making seltzer. They're really well built and seal perfectly.

This is a very well made product, and feels absolutely solid. I suppose that is because it is solid stainless steel. Some things to know:* I bought the "qty 2" item, and I got two caps. Go figure.* It is a two part ball lock cap, the hose barb on bottom unscrews and has its own O-ring.* On my copy the two slots on the side were not machined. (In my picture, I point to it with a pencil) That caused a sharp barb that simply needed to be removed with the touch of a file.* It screws onto standard 2L soda bottles very securely, the threads are perfect!* It is a great value for the price (it would cost you 4-5x to have this part made)* It is completely serviceable, the pin lock and preload spring are retained on the bottom by a retaining wire (not a retaining ring)This product is highly recommended, well made, and a great value.* For each cap you get a set of replacement O-rings.With carbonated beverage in hand, cheers to you!

Oh my goodness are these things built!Their dimensions are spot on for use with multiple charge connectors. They do not require any kind of force to seal at up to 65/70# (most I’ve tried). The will last forever!

We make seltzer using a CO2 tank. We had some plastic caps that gave us lots of issues (like not fitting the bottles).These caps are excellent! They for nicely, are extremely heavy duty and look nice too.The rubber gaskets occasionally fall out when opening the bottle, but it's not a big deal. We've bought them several times already. We're super happy Anna highly recommend them.

I purchased this because I wanted to have more of these with the barb because it seemed to perform better in terms of keeping the gasket in place.This was the best value for the money and worked really well.The only real issue I realized much later is that the polished finish makes it harder for the hand to grip it when removing. Not a big issue, just need to focus more (and use more than 1 hand).Great quality though.

It performes as described.

You need a co2 tank ball lock gas fitting and regulator. They work great and are well made. You also get xtra O rings and washers.

When my old blue plastic CarbaCap started to leak because of a hairline crack, I was pleasantly surprised that SS metal versions were now available, and at a price close to the original plastic version. Curious if there was any difference between the similar looking versions at Amazon, I purchased both the single Ferroday and the MrBrew two pack. The metal parts are identical, probably coming off the same machine in the same factory in China. The only difference is in the number of spare o-rings. Ferroday includes 5 small Ball Lock o-rings and 1 large bottle flat washer. MrBrew has 8 small o-rings but Zero flat washers. This is weird because the flat washer can fall out and get lost while the small o-ring will probably last a long time. Neither brand includes a spare o-ring for the 5/16 barb fitting, although being screwed inside it is well protected.