Helicoil for spark plug. Anyone know what size?

[sportline]

My car has been in the garage all week waiting to have a helicoil put in where the plug blew out. Its a clio cup 172. They're having trouble getting one the right size. I was wondering if anyone new the actual size they should be looking for so I can try and source one and better still if anyone knows where I may get one.
Thankyou

 

[ABOO]

Don't quote me mate, but pretty certain it's 14mm. If you search, I know sideways Danny has posted size before, could always PM him. Did it cause any other damage? Number 3 by any chance....
Make sure garage know what they're doing, it's not as straight forward as it may seem, or so I believe...

 

[sportline]

I hope they know what there doing, but wont know till i get it back. very frustrating.