what supply system is this

[Guitarist]

Looks like part of the head to me, especially as it's on the neutral side, so TNC-S.
Love how you managed to capture the spider as well

 

[mblaquière]

Haha I had to get the little guy in there too! The g+y at the top is just one of the ones terminated in the MET. Ah ok I didn't think about that! I didn't expect the MET to be able to be attached to the head but that makes sense! Thanks guys! That would make the supply cable to be swa but it looks very thin for swa? What is the minimum size you can get? Thanks for clarity again guys much appreciated!

 

[trev]

Could be a split concentric

 

[Guitarist]

What trev said

 

[Engineer54]

Could be a split concentric

It is, (or a straight concentric) far too small to be a PILC cable!!