PPRuNe Forums - sennheiser HMEC 25KA, Mike plug wiring

Does anybody know what the 4 coloured cables should be connected to on a replacement Mike jack plug. For the above headset?
Im replacing due damaged plug.

I’m replacing a stereo jack with a replacement from Maplin; the plug appears identical.
There are 4 cable colours

Blue
Red
Black
Yellow
& copper (I’m assuming a shield).

It looks like the Blue & Yellow connect to the central core of the plug
& Black to the outer of the plug.

Where do the Red & Blue (& copper) attach to; they became dislodged during cutting the cable?

Thanks. C