ZRDR CO2 High Pressure Reducing Cylinder Valve w/ Solenoid (W21.8) Part #R104
 
CO2 Bottle attachment is (W21.8) fitting
Accurate fine-tuning (regulate to 1 bubble/2-3 sec)
Fixed Fine Tunning Value
Material: aluminum alloy and acrylic
Dual gauge pressure indicators (tank volume and flow pressure / working pressure)
Includes - Single head bubble counter - Part # W00-02A
Includes - Solenoid Controller 
Includes 110 Power Supply / Plug
Approx size: Height 3" inches, Width 1" inch