Features 1、Made of high quality brass material, durable and long lasting. 2、It allows you to attach a paintball CO2 tank to your existing keg system CO2 regulator. 3、Stable, quiet and no noise. Can be used for CO2 regulator at the aquarium. 4、Easy to install, just twist by hand, no high installation skill required. 5、2 sizes available, you can choose the right one you need. Great kits for your aquarium tank. Features: 1. Made of high quality brass material, durable and long lasting. 2. It allows you to attach a paintball CO2 tank to your existing keg system CO2 regulator. 3. Stable, quiet and no noise. Can be used for CO2 regulator at the aquarium. 4. Easy to install, just twist by hand, no high installation skill required. 5. 2 sizes available, you can choose the right one you need. Great kits for your aquarium tank. Specification: Condition: 100% Brand New Material: brass Color: as pictures shown Type: 1, 2(optional) Type1: W21.8 convert to CGA320, inner thread: W21.8; out thread: CGA320 Type2: CGA320 convert to W21.8, inner thread: CGA320; out thread: W21.8 Diameter: 2.8cm/1.1in Package list: 1 * CO2 Tank Adapter Package List