Lees MK23 suppressor adapter

[allicorn]

This little Lees Precision adaptor for the MK23 to take its 16mm thread down to a 14mm, available by auction or on one or two UK retailers' sites: will it fit on a KSC M11? I kinda doubt it, but I figured it might be worth asking.

If you've got one of these little doodads, any chance you can measure the internal diameter at its smallest point?