The Craft Master integrated CO2 regulated growler cap is the premier way of keeping your beverages fresh and carbonated in one of our luxury pressurized growlers! Each regulator cap features a smooth CO2 regulating knob, color coded PSI pressure gauge, safety valve, and a zipper tab for easy pressure release. Designed exclusively for the Craft Master line of growlers each heavy duty regulator cap is crafted to the highest specification out of the finest food grade materials and designed for long lasting durability. Cleaning the cap is easy, simply give it a thorough rinse with hot water. Both the cartridge holder and the cap itself are designed to create a perfect air tight seal on your growler without the need for excessive tightening (hand tight only). This secure seal will keep your beer and beverages fresh for days or even weeks (we recommend emptying the container within two weeks). We should also note that each cap will gladly accept either of our 8 gram or 16 gram food grade CO2 cartridges and comes complete with both sized holders.