Description: Do you want to make your fish tank different? Our new designed carbon dioxide bubble counter is a good choice for you. Made of high quality material, which will be durable and reliable. With non-return function to prevent the backflow when the pressure changes. It can help you to see clearly the volume of carbon dioxide and supply the plants with enough carbon dioxide. Features: 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. Specifications: Condition: 100% Brand New Item Type: Bubble Counter Material: Aluminium Alloy & Acrylic Color: Silver Double Head Size: Approx. 8.2 * 2cm / 3.2 * 0.8inch(L * D) Single Head Size: Approx. 8 * 2cm / 3.1 * 0.8inch(L * D) Package Weight: Approx. 32~34g Install Method: Single Head Bubble Counter: 1. Take out the seal ring and install on the trachea interface of the valve, then tighten the bubble counter. Double Head Bubble Counter: Package Include: 1 x Bubble Counter