We have 4 types of regulators. All do basically the same job, reducing the pressure of gas going through them from a gas bottle to the level you need to go into your keg.
The iKegger 2.0 | Multi-Gas Mini Regulator: The new kid in town is also the most versatile. As the name suggests you can use CO2, Nitrogen, or Nitrous oxide bulbs with this regulator. All of them fit in the included bulb holder for unthreaded bulbs. Also included is a threaded inlet to allow 16g and 25g CO2 bulbs and adapters for larger gas bottles to be used (CO2, N2, and Argon). A swivel adapter is built in so the regulator angle can be adjusted easily and also included is a steel check valve to prevent liquid from damaging the regulator if it's used lying down. A steel gas ball lock disconnect is also included with it.
The iKegger 1.0 | Mini CO2 Regulator: for years this was the best mini regulator in Australia. We can say this without any doubt. We've tested all the others and if you don't believe us check the reviews on our competitors' ones (oh yeah, they don't have any published...). These natively use a 16g or 25g threaded bulb but we have adapters that enable it to be used with both 400g Sodastream gas bottles and refillable type 30 CO2 bottles. The remote gas line allows it to be used separately to a keg instead of directly attached to it.
Dual Gauge Regulator: designed for use with large refillable CO2 gas bottles. The standard thread for these is a Type 30 thread in Australia. The main advantage is you can see the pressure remaining inside the gas bottle and the refills are cheap (but the initial bottles are usually $80+). We have adapters for it so you can use 400g Sodastream gas bottles as a semi portable option and an M10 adapter that allows using disposable 2.2L pure nitrogen or CO2 gas bottles with it.
The Inline Regulator allows you to reduce the pressure in a gas line, for instance, if you want two different pressures to different kegs (a stout and a soda) you can run your main regulator at the higher pressure and use the inline one to reduce the pressure going to the other keg.
The Spunding Valve & Autostop Filler (which includes a spunding valve) are for releasing any excess pressure above a level you set. While brewing in a pressure fermenter this allows you to release the excess gas produced while keeping the correct pressure inside to carbonate your brew. With the auto-stop filler it allows you to set the release pressure at slightly lower than the pressure in the full vessel so the liquid transfers slowly to the empty one without losing carbonation.