Bosch chainset lockring tool – but which one

Trying to help a mate whose chainset lock ring keeps coming loose.

Like a twit I just googled, clicked and bought an IceToolz M801 but it’s too big for the ring.

The ring is stamped 2021-04

Any idea which tool I(he) need please?

The other number on the ring is ‘1 270 014 095’

Do you mean one of these?

https://www.ebikemotorcentre.com/product/bosch-gen-4-lockring-tool-sprocket-nut-tool-part-no-pla00930/

Possibly, but not sure what gen it is.

Does it have a small chainring around 18 teeth (Gen 2) or a large chainring around 34 teeth ( gen 4) ?

Either way a drop of blue locktite normally stops then coming loose

You’ve lost me on the number of teeth bear. It’s got 8.

I managed to get a shitty park tool that needs an 8 sided socket, or effing big spanner, 20mm across the flats.

So went for the effing big spanner and loctite. Who wants 8 sided sockets apart from hgv drivers.