The carbonation cap is highly effective to add and maintain carbonation in beverages for extended periods of time. The in-built 5/16inch Bart can attach 5/16inch ID tubing and a 0.5 Micrometre carbonation stoneto attach on with the portability of being to move the cap from bottle to beer bottle. Stainless last forever. Compared with the traditional bottling, kegging, and home seltzer machines,save more time and money Simple to use,fill a standard 2L bottle with homebrew (or liquid), attach the cap and CO2 system, and shake. Carbonating home brew has never been easier! Use a standard plastic bottle and this carbonation cap for an easy and effective carbonation process. Product Type:Carbonation Equipment Type:Stainless Carbonation Cap Model:Counter Pressure Bottle Filling cap Condition:100% Feature:carbonation cap ball lock With:ball lock/clamp usage:Homebrew beer Juice,water Quality:Top Fits:Most Soft Drink PET Bottles color:Black + silver Material:stainless steel + plastic Package Contents: 1 x acid cap 1 x Ball lock distributor Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.