Piston Ring Size

[mojobaby]

Can anyone advise me on which piston rings I should be ordering for my car. The piston size is 58mm.
My oval plate says my car is 1123 which is an 800 engine.

The piston sizes which are available are thickness 2x2x3,5 or thickness 1,75x2x3,5. What do these measurements pertain to? Do they mean to say "width" ? Are these the measurements on one ring or the measurements of 3 different rings?

I have an oil ring which is quite wide. The top ring is also narrower than the second(middle) ring.

 

[Geoff in the Gully]

The sizes refer to the thickness of the three rings starting with the top one.
You would have 1,75 for the top ring.
I think a 2mm top ring is for when a worn top grove in a piston has been repaired by machining it wider - to 2mm.

 

[mojobaby]

OK thanks Geoff, its a bit clearer now. 3 rings and 3 "thicknesses"!