3" Mortar, will this plug fit this ?

[Gspragge]

Or do I need an adaptor or a different plug. The colour seems blackish so I
assume a practice ? If this plug is of no use does anyone have a correct one.
If I need an adaptor it is likely a lost cause.

 

[Gspragge]

Or do I need an adaptor or a different plug. The colour seems blackish so I
assume a practice ? If this plug is of no use does anyone have a correct one.
If I need an adaptor it is likely a lost cause.

It would seem that there is a plug for this situation -

 

[Gspragge]

Silly question I suppose, but does anyone have a spare plug of this type ?