Features: 100% Brand New and High Quality DIY Co2 generator system D201 Pre-connection， avoid wrong connection High quality bottle caps， good pressure resistance， NO deformation Promoting plants growing， easy to set up， low cost， safe Universal design， fits most tanks or aquariums Model: Regular (D201) Material: ABS With 2 air-pipe locks on the bottle cap， prevent the air-pipe get loose Specialized pressure gauge， safe area and scale can be seen clearly Fine adjustment valve， adjusts Co2 discharge， Co2 can dissolve in the water fully Other material you need to prepare (NOT included): 200g x Citric acid powder or Vinegar 200g x Baking Soda powder 2 x Soft drink bottles (2 Liter)Package Includes: 1 x Needle Valve 1 x Pressure Gauge 2 x Bottle Caps with Air Tubing (Section A and Section B) 1 x Extra Air Tubing 1 x Instructions