Feature: 1. Professional CO2 generator system with stainless steel bottle, better than simple plastic bottle generators. It is more dependable, stable, enduring and efficient. 2. Safety valve will open automatically when the pressure over the safe pressure. 3. Bubble counter with check valve: Discharge rate of CO2 indication device and stop water flowing back into the regulator. 4. Large amount of CO2 may cause fish dead. It is recommended to reduce the CO2 volume at the beginning, 1 or 2 bubbles per second. One time\u0027s reaction can last for 3 to 4 weeks using. 5. Any problem, please call our store without hesitation. Pleased to serve you! Specification: Specification: Name: CO2 generator system Main material: Stainless steel Main color: Silver 2L: Height: 37 cm; diameter: 10cm; thickness: 0.12cm; Basic material ratio： 2L: Citric acid 200g+baking soda 200+water 300g Packing size: 15 * 15 * 44cm Packing weight: 2L: 1840g . Package List: 1 x Stainless steel bottle 1 x Pressure reducing valve 1 x Bubble counter with check valve 1 x Pressure gauge 1 x Built in safety valve 1 x Fine adjusting valve 1 x ABS multiple filter 1 x 1.5m tube 2 x Suction cup 1 x Manual Note: Excessive or double addition of basic materials and water is prohibited. Invert the bottle and disassembly are prohibited.The appearance of the pressure gauge is random.