DIN, yoke...choosing a reg isn't a joke!
Yoke regulator 1-st stage - on left, DIN - on the righ.
A DIN regulator screws into a tank valve, and a yoke regulator fits over the top of a tank valve and clamps onto it with a tightening screw.
Yoke and DIN Regulators Require Different Tank Valves: yoke regulators use a more-or-less flat tank valve that has an o-ring pressed into a small grove on the flat side of the valve. DIN regulators use a tank valve with a large, threaded opening that allows the threaded post of a DIN regulator to be screwed inside the tank valve.
DIN regulators are designed to withstand higher pressures than yoke regulators. It is possible to knock a yoke regulator off the tank if the tank is dropped or struck (not an ideal situation). This is nearly impossible to do with a DIN regulator. DIN regulators are also more streamlined than yoke regulators, and generally weigh less.
Our verdict: DIN system is by far superior. It unquestionably provides a more secure and durable connection.
P.S. Adaptors are available to use DIN regulators on yoke tanks and vice versa.