Oil change rubber o-ring sizes

It's oil service time. Does someone know the rubber o-ring sizes for the engine sump plug and gearbox sump plug? I know they are reusable, but I'd like to replace them.

I don't think the are O section , more of a lipped or wedge seal ?

So I'm half way through my oil change. Looking at the engine oil sump plug it has DIN 3869 M14x1.5 NBR. The gearbox oil sump plug seal doesn't have anything written on it. This seems to translate to fluid connector seals. The NBR means Nitrile. I've ordered M14x1.5 and M10x1.0 for the plugs. Could only find Nitrile and would have preferred Viton, but it is what's used currently. The gearbox seal is proud of the plug so would still seal. The engine seal is flush to the plug so does look like it needs replacing. This could explain very slight oil mist around the plug.