These CO2 bottle caps are designed to be replaceable way for maintaining your CO2 system. Instead of replacing the entire generator, you can simply swap out the caps as needed. This feature that your CO2 system remains in condition, providing consistent performance for your aquarium. Features -Color:Beige -Material:ABS -Size:3.30X3.30X3.00cm/1.30X1.30X1.18in -Leak prevention: quick tightening design a secure seal, preventing co2 leakage and maintaining gas purity -Wide compatibility: precision manufacturing compatibility with multiple standard co2 cylinder interfaces -Robust construction: made from high pressure resistant materials, ensuring the stability of the cap and bottle -Portable and lightweight: small and easy to carry, for outdoor activities such as barbecues and camping -Long term co2 storage: efficient sealing technology reduces gas loss, extending the usage time of co2 inside the bottle for long term storage Package list: 10 x bottle cap