Description: Made of high quality material, which will be durable and reliable. With non-return function to prevent the backflow when the pressure changes, and this can ensure the water plant table and CO2 bottle from damage. It can count the volume of carbon dioxide and supply the plants with enough carbon dioxide. East to install and use, a good choice to make your fish tank different. Double head and single head are available, you can choose according to your needs. Specification: New and high quality Product Name: CO2 metal check bubble counter Material: stainless steel Color: as shown in the figure Package Included1PCS Note: 1. Due to manual measurement, please allow an error of 1-3mm. 2. As different computers display different colors, thank you for your understanding, the actual product color may be slightly different from the image.