Direct Info from Product Website : https://www.co2art.eu/collections/co2-regulators/products/advance-professional-aquarium-co2-dual-stage-regulator-and-solenoid-magnetic-valve

Built for aquariums from 5 liters to 5000 liters!

Dual stage construction minimise increase in output pressure as pressure drops in gas cylinder and will prevent end-tank-dump no matter what size CO2 cylinder you will use.

New fully customised solenoid block with integrated high precision needle valves and bubble counter.

Features :

Safe 12V DC Integrated Solenoid Valve
Power adapter with universal voltage 100V-240V
Adjustable working pressure up to 5 bar
Stainless Steel Dual gauge pressure indicators (tank volume and flow pressure / working pressure)
High precision integrated needle valve
Bubble counter with built-in check valve
Extendable manifold block
Due to Two Stages construction compatible with any size CO2 Cylinders.
The thread is made according to UK, Europe, Japan, Taiwan standard (BS341 / DIN477 / W21.8×14) or CGA320 thread.
Looking to inject CO2 into two, three or more aquariums ?
Your Aquarium is +500L and requires more diffusers ?

Now you can add as many outlets as you like. With easy installation you can add or remove additional blocks anytime you want.