100% brand new and high quality Features: Made of high quality of materials. Use with CO2 indicator. Easy to use and convenient to detect concentration of CO2. Suitable for all kinds of fish tank. A wonderful solution for feeding fish and observing their living condition. Different color of liquid represents different concentration of CO2. BLUE means that CO2's concentration is too low. GREEN means it is normal. YELLOW means that CO2's concentration is too high so that it is harm to fish. CO2 indicator Solution Liquid and Detector only,other accessories demo in the picture is not included. Specification: Material: Glass Bottle Height: app.7.7cm/3.03in Inner Packaging Size: app.11.5x11.5x4cm/4.53x4.53x1.57in Net Weight: 15ml Color: As the pictures shown Quantity: 1 Set Note: 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 Contents: 1 x CO2 indicator Solution Liquid 1 x Detector