Correct, the diver supplies the oring with DIN since it is attached to the regulator. Advantage #1What Dan G said, plus the O-ring is on the regulator, not the tank. So you're not at the mercy of a bad tank O-ring. Last, like Dave said DIN can handle higher pressure tan
The max working pressure of DIN is 300bars / 4,350psi, for yoke it is 240bars / 3,400psi. Advantage # 2
It is also bit more compact.