This item is a simple and practical CO2 generator system which is special designed for fish tank. It helps promote plants growing, easy and safe to set up. With pressure gauge, safe area and scale can be seen clearly. This bottle is very well suitable to be DIY CO2 system’s accessory that the size fits common PET plastic bottle. The complete DIY CO2 kit combo for planted aquarium. Features - ColorWhite - Material: Plastic & Metal. - Size: Approx. 19x13.5x4.8cm. - This bottle is very well suitable to be DIY CO2 system’s accessory that the size fits common PET plastic bottle. - The complete DIY CO2 kit combo for planted aquarium. You can built up your CO2 system within 15 mins. - Promoting plants growing- easy to set up- - safe. - With 2 air- locks on the bottle cap- prevent the air- get loose. - pressure gauge- safe area and scale can be seen clearly. - To building up the system- you need to prepare some materials below (not included): 200g of Citric acid powder or Vinegar, 200g Baking Soda powder, 2x drink 2L bottle(2 Liter) Attention - The bottle have to use carbonated beverage bottle- do not use pulpy- green tea- mineral water bottles- etc. - Trimming regulation avoid by sudden big or small- do not suddenly turn up- after immediately shut down again so as not to cause abnormal pressure to the bottle. - Make sure carefully observe the direction of the parts before assembly. The usual wrong handle way will cause abnormal reaction components as follow: the contrary direction of the check and fine-tuning in . Package list: 2 * Aquarium Planted Tank DIY CO2 System Kit D-201 Generator 2 * Extra Air- 2 * Manual