I think the diameter is printed on the hose . Look at a clean piece-maybe
near the evaporater What you might do is to go ahead and make your cut and
take one piece to a junk yard.This is american hose and is not metric.Cut
some hoses in the junk yard and match it up. There are only a few sizes to
choose from. Once you know your size, find a late model vehicle and cut
your replacement hose from that.Look around. You will need a barbed fitting
to splice the 2 pieces. This and some hose clamps is acceptable.Gotta be
barbed.The fitting can be ugly on the outside.A a/c shop can do this for
you if that is the way you want to go.Also,a place that does hydrolic
hoses.Roger