Bar end plugs - skinny fit?

[DynatechFan]

Bit of an odd request, I am after some bar end plugs that will fit in to a thick walled handlebar - cant find anything skinny enough for sale anywhere, none of the (many) spares I have will fit. Bars are about 3mm wall thickness (!) and it looks to be about 12mm i.d.

Not sure where the handlebar came from, its definitely bicycle but I do have a lot of boxes of bike parts from years of tinkering so heaven knows what bike it came off. Built my ebike up from bits in the garage and these bars were the strongest ones not in use. They did have "normal" rubber grips that wrap around the end of the bar, but just swapped to lock on style Ergos - super comfy - so right now the handlebar ends are open to the weather

 

[JPGiant]

I've tried a few manufacturers of bar ends and the all clamped on the outside diameter of the handlebars.
Do you mean handlebar plugs that fill the hole, like these...
https://www.ebay.co.uk/itm/Alloy-Road-Bike-MTB-Cycling-Cycle-Handlebar-Bar-Cap-End-Grip-Handle-Plug-Cover/323263387317?hash=item4b43ffd6b5:m:mCbxUSd0r_gLTj86OrOuYzw:rk:1:pf:0

... you could shave a bit from the internal expanding grips if required.

 

[DynatechFan]

sorry for any confusion, yes its just plugs

have tried bodging with the stuff I have (including similar plugs to link but not the same) and they are all too big, 12mm is proving tiny.

Will have a rummage on ebay, if the expanding rubber bit is bodge-able should be able to make it work

 

[JPGiant]

Here we go...
https://www.ebay.co.uk/itm/Round-Plastic-Blanking-End-Cap-Caps-Tube-Pipe-Inserts-Plug-Round-Tube-Plugs/232800417092?hash=item3633fc7544:m:m6rw25gszkj19qq8_rd19aQ:rk:1:pf:0
Look for 12mm tube end caps on fleabay - many sizes, colours, amounts - cheaper from Hong Kong, the choice is yours.