Our CO2 bottle caps are designed to provide a secure and efficient seal for your DIY CO2 systems. These caps are made from plastic, ensuring use and reliability. They are for aquarium enthusiasts who need a dependable way for their CO2 generation needs, enhancing the health and growth of aquatic plants. Features -Color:Beige -Material:ABS -Size:3.30X3.30X3.00cm/1.30X1.30X1.18in -Note: inner diameter: 2.8cm -Quick tightening design: a secure seal on the bottle mouth, preventing co2 leakage and maintaining gas purity -Precision manufacturing: compatible with various standard co2 cylinder interfaces, enhancing user convenience -High pressure resistant: made from high pressure resistant materials, ensuring stability of the cap and bottle structure -Compact and lightweight: easy to carry, ideal for outdoor activities like barbecues and camping where co2 cylinders are needed -Efficient sealing technology: reduces gas loss and extends the usage time of co2 inside the bottle, suitable for long term storage needs Package list: 20 x bottle cap