Our carbonation cap is made of 304 stainless steel material and liquid ball lock is made of high-quality plastic material, sturdy and durable to use. With this cap you can simply fill an old PET bottle with cold liquid of your choice and carbonate by connecting your Liquid ball lock disconnect. It is designed to fit most soft drink PET bottles. So you could make your own soda water, carbonate beer or other soft drinks, easy and convenient. Specification:Material: Stainless steel + Plastic Color: Sliver + White Carbonation Cap Size: 6 x 3.2 cm / 2.4 x 1.26inch (appr.)Liquid Ball Lock Size: 5.5 x 3.6cm / 2.17 x 1.42 inch (appr.)Liquid Ball Lock Under Diameter: 2.9 cm / 1.41 inch (appr.)Liquid Ball Lock Top Diameter: 2.3 cm / 0.91 inch (appr.) Package Included: 1 x Carbonation Cap 1 x Liquid Ball Lock The carbonation cap is made of 304 stainless steel, which is a very effective method to add and maintain carbonation in beverages for a long time The carbonated cap is a screw cap with integral Cornelius ball lock accessories, which is easy to use The stainless steel carbonized cap is designed to fit most soft drink PET bottles You can simply fill an old PET bottle with cold liquid and carbonate of your choice, and the stainless steel carbonized cap is disconnected by connecting your liquid ball lock With our stainless steel carbonized cap, you can make your own soda water, carbonated beer and even soft drinks