On Sunday, 5 January 2020 20:43:25 UTC, Robin wrote:
I visited a HH5 today. FWIW PSU was P/N 19118836, model no.
S018RM1200150, "for use with BT Home Hub 4 & 5 Type A"; my cheap
Workzone caliper gauge showed an external barrel diameter of 5.44mm; and
measured the diameter of a screwdriver which was a sloppy fit inside as
2.88mm.

Thank you. So I definately need a pin hole bigger than 2.1mm.

Owain