Well look no further because I have exactly what you are looking for. Not only that but I thought a YouTube clip might help explain the reg a bit more and I also show a pretty cool feature on it which you will find out when you click below.
Using a CO2 fire extinguisher is one of the best ways to use CO2 in your planted aquarium. You can also use pub style CO2 bottles as they also have the DIN477 connection piece. Ensuring plentiful CO2 is a major reason for hobbyists to have successful planted aquariums, and if you make it limit you (because of the cost) you will always struggle. By using cheap gas cylinders you will ensure the correct CO2 levels at all times (at very little cost).
Let me know what you think as all questions are welcomed. And if you want to see the product click on this link which will take you to the correct page on our site http://www.aquaessentials.co.uk/easy-aqua-twin-guage-regulatorsolenoid-p-6179.html