Check the listing for details. SR Aquaristik Single Stage CO2 Regulator for Aquariums & Calcium Reactors. Condition: New. Listed at 139.98 USD. SR Aquaristik Single Stage CO2 Regulator/Bubble Counter/Solenoid Valve Kit For Aquarium Plants Calcium Reactors Ideal for planted aquariums and calcium reactors Precise control of CO2 output Displays canister pressure & CO2 output Compatible with most ph controllers and standard timers Product Description: The SR Aquaristik Aquarium Single Stage CO2 Regulator Kit is used to regulate the flow of carbon dioxide from standard North American CO2 bottles. Ideal for use in planted aquariums or for supplying CO2 to calcium reactors for reef aquariums or any other applications that require a precise CO2 control. The CO2 regulator comes complete with on/off solenoid that can be used with a pH controller or timer, bubble counter and extra regulator seals. Customer Reviews: Tong on Feb 23, 2021 Solid stainless steel and brassThe product is built good. In solid quality. Kyle on Mar 21, 2020Outstanding Customer service!Had a minor issue that was resolved immediately with no questions from the owner. He contacted me directly and fixed the minor issue I had. I will definitely come here in the future if I need any of the products they sell.RETURN POLICY: We want you to be happy with our products! If you are not 100% satisfied with your purchase, you may return it for a replacement or a refund of the full product cost. It's part of our no-risk customer guarantee! (please see the details under the Shipping & Payments tab)