Aquarium Co2 Regulator Dual Pressure Gauge With Bubble Counter And Solenoid Product Features Electromagnetic modular design, can be disassembled and used alone Micro solenoid valve, the temperature is much lower than ordinary solenoid valve Unique structure design, fixed without wrench, freehand operation High precision structure, precision pressure gauge The interface is standard CGA320. This pressure gauge is suitable for filled gas cylinders only, not chemical CO2 cylinders. ?Use tip?The solenoid valve needs regular maintenance. When the solenoid valve can't control the CO2 flow, it needs to be cleaned before it can work normally. Please Email us for guide video: The solenoid valve needs regular maintenance Shipping: Shipping is complimentary within the lower 48 US States. We Do Not Ship to PO/APO Boxes, HI or Alaska We Do Not Ship Outside of the Continental US All items ship within 24-72 hours of Payment For large items that require Freight shipping a valid phone number is required to call and schedule your delivery Terms of Sale and Feedback: Feedback is extremely important to us and If you are satisfied with our transaction, please take a moment to leave Positive Feedback. YOUR Satisfaction is our #1 Priority! If there are any issues, PLEASE contact us BEFORE leaving a neutral or negative rating so that we may resolve any concerns. We PROMISE we can make you happy if you give us a fair chance. Returns / Concerns: All items qualify for returns within 14 - 30 days of receipt. Buyer is responsible for return shipping on any item that is not damaged Please be sure this is an item you want before making your purchase. Customer Satisfaction is our TOP priority! All items are IN STOCK at time of listing. Inventory changes constantly and it is impossible to maintain a perfectly accurate count of all items. Please do not penalize us if we have to issue you a refund! Thank You For Your Business!