7/8 ths of an inch is the standard measurement for clipon bars.
Just know that these will not be easily
compatible with all
These carbon tubes are designed to slide into brackets that attach to the top of the fork.
Like these (note that 50mm is the wrong size for an F4 fork, it's just an example): http://motowheels.com/i-6921907-moto...-ons-50mm.html
My F4 750 from 2000 has the original two piece
version that these carbon clipons would be compatible with (See picture 1).
Recent versions of the F4 have a one piece
clipon / tube design (See picture 2)
The carbon bar above will not work with these. You'd have to source the adapter that allows the 7/8 ths carbon tube to be installed and then consider how to mount your clutch & brake master cylinder fluid reservoirs.
Also know that the carbon tubes come in one length only and you'd need to test fit / measure / cut to length.
I'm pretty sure that these carbon bars will not work with any of the F4 1000 series without further expenditure.
I have a set of these on my 2002 R1, sourced from Motowheels in 2006 from their trade stand at the Laguna Seca MotoGP. They are a very nice component.