Feature:1. Use color to determine how much CO2 fish tank needs to add at a glance, to help the novice to determine the appropriate dosage of C02.2. More real capacity than similar products, more accurate and easy to use.3. Different from similar products, neeed to add the yellow base liquid for reused of the water in the cylinder, the initial color of this monitoring liquid is blue.4. Direct drip can be used, more convenient, more scientific, truly worry-free.5. Made of high quality material, sturdy, durable and long service life.Specification:Condition: 100% Brand NewItem Type: Aquarium CO2 IndicatorMaterial: GlassColor: As Picture ShownLiquid Content15mlWeight: Approx. 53g.Package List:1 x Aquarium CO2 Indicator1 x Indicator Liquid1 x Suction CupNote: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.