Features: This CO2 aquarium regulator can assist your aquatic plants in their growth cycle. Always inject the right amount at the right time to keep your plants growing the right way. The large display allows for easy reading of your settings to ensure that they are always where you want them to be. The precision construction of this regulator will ensure that you can always fine tune the amount of CO2. Perfect CO2 aquarium regulator to create the best growing conditions for your aquarium plants. Package list: Material: Aluminum alloy Color: Silver Suitable interface: w21.8, g5/8(Optional) Size: 6 x 7cm / 2.4 x 2.8 inch(Approx.) Package list: 1 x CO2 aquarium regulator Note: Adjustable fine-tuning valve to control the size of the air output, or a separate bubble counter accessory (product not equipped) Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering. 1,This CO2 aquarium regulator can assist your aquatic plants in their growth cycle. 2,Always inject the right amount at the right time to keep your plants growing the right way. 3,The large display allows for easy reading of your settings to ensure that they are always where you want them to be. 4,The precision construction of this regulator will ensure that you can always fine tune the amount of CO2. 5,Perfect CO2 aquarium regulator to create the best growing conditions for your aquarium plants. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.