5/16" barb of carbonation cap is to connect the hose and diffuser stone. Carbonation cap can be connected with gas and liquid quick disconnect, then connected to beer and gas hose, mini keg regulator, beer tap and PET bottle.
eBay
AW2000-02 Pneumatic 1/4 BSP Air Filter Pressure Regulator Combo Piggyback, Air Tool Compressor Filter with Gauge
Aliexpress UK
Summit 15" Wide Built-In Nitro-Infused Coffee Kegerator SBC15NCF. Sized at 15" wide, it features a front-breathing design for built-in installation under counters and a fully finished cabinet for freestanding use.
eBay
1/4” Spray Paint Gun Air Pressure Regulator Pressure Gauge Pneumatic Tool Accessory
Aliexpress UK
This gauge is suitable for Duotight inline regulator. These mini gauges are accurate to about 10% of the range of the pressure gauge. So if you use the lowest range possible it will ensure the best possible accuracy. Also these gauges are quite easy to install into a tank and depending on the thickness of the tank wall all you need to do to fit a Gauge like this is drill a hole in the tank about 8mm in diameter then insert the gauge and secure with screws. .
eBay
2Pcs Universal Car Door Window Regulator Glass Support Clips For Auto Slider Sash Connector Holder Clip Car Door Glass Clip
Aliexpress UK
The Micromatic Pressure Regulator for Kegerator New is a high-quality product designed for precise control of beer pressure in a kegerator system. With a 1/4 inch hose inner diameter and outer diameter, this D Tap model from Micro Matic ensures smooth and consistent dispensing of your favorite brew. Ideal for use in restaurants, bars, and other food service establishments, this pressure regulator is a reliable and essential component for any draft beer dispensing setup.
eBay
8pcs/pack 2020 Aluminum Block Cube Prism Connector Wheel Regulator Corner for 6mm Slot Aluminum Extrusion Profile 2020 Series
Aliexpress UK
Build your own KEGERATOR or KEEZER! Our DIY Kegerator Conversion Kits make it easy to quickly and economically transform any suitable refrigerator or freezer into an amazing beverage dispenser! This high quality dual gauge CO2 regulator is perfect for draft beer dispensing, and ideal for kegerator conversions!
eBay
2 In 1 Co2 Charger With Converts Adapter For TR21*4 Co2 Cylinder,0-60Psi Mini Co2 Regulator For Co2 Cartridge
Aliexpress UK
This regulator features a Y splitter and two shut offs WITH CHECK VALVES that eliminate beer from backing up into the regulator causing a failure.
eBay
90-120PSI AC Air Compressor Pressure Switch Valve Control Kit Vertical Switch Manifold Regulator Gauges Safety Valve
Aliexpress UK
eBay
EU AR2000 1/4" Thread BSP Pneumatic Air Compressor Pressure Regulator Reduction Valve 4MM 6MM 8MM 10MM 12MM Connector Fittings
Aliexpress UK
• Draft beer dispense systems. ✔Suitable for standard CO₂ cylinders used in beer dispense. TecFlo CO₂ Bottle Mounted Primary Regulator. Preventing flat beer. ✔Bottle mounted design – connects directly to your CO₂ cylinder.
eBay
For Surron Electric Bike Motorcycle Rear Axle Block Chain Regulator Adjuster Bolt For Sur Ron Light Bee Accessories
Aliexpress UK