AC adapter for Acer Aspire E1-572 - DC jack plug size (internal diameter) ?

Dear Acer Community

AC adapter for Acer Aspire E1-572  - DC jack plug size (internal diameter) ?

I am trying to get a replacement dc adaptor for an Acer Aspire E1-572.

(serial number starting NXMBEEK02934 ... it's possible that I may read zeroes as O's or vice-versa)

I cannot find anywhere what the DC jack plug internal diameter should be.

Some indications are that it is 5.5mm / 1.7m

Other indications are that it is 5.5mm / 1.5m

Other indications are that it is 5.5mm / 2.5m

+ related

I have a possibility of using a dc adaptor for an Acer Aspire E1-571 with a 5.5mm / 1.7m DC jack ...

but most suppliers seem to sell different adaptors for E1-571 and E1-572,

and although I can't quite see the difference (unless it is the DC jack plug size) I assume there must be a reason for that

Can anybody advise ?

Thanks in advance

Ed