Description: brand new and high quality Features: High quality, durable and not easily damaged. Precise structure made of durable copper that regulates the release of CO2. Special copper-grinded surface, light weight, easy to operate. Ergonomically design, easy to install without using any tool. 2 styles are available to suit different needs. It features a non-return function to prevent the backflow when the pressure changes. Co2 regulator for valve applies nut lock design can effectively lock the CO2 tube, to prevent the accidents caused by loose. Aquarium Valve-Regulator Diffuser Single-Head/Dual-Head CO2 only, other accessories demo in the picture is not included! Specifications: Material: Copper Optional size: Single for head, Double for head Single for head size: app.3.8x2.9cm/1.50x1.14in Double for head size: app.4.3x2.9cm/1.69x1.14in Color: As the pictures shown Optional style: Single for head, Double for head Quantity: 1Pc Note: No retail package. Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package Includes: 1 x Aquarium Valve-Regulator Diffuser Single-Head/Dual-Head CO2