See photos.
I purchased a "lot" of windsurf gear as I am picking up the hobby/sport.
I will never need a cambered sail like this for racing or high performance.
It does not have a size, but I've seen it rigged only last year.
It is a decade or two old and there are some repairs that have been done.
Model 6.0 m ECLIPSE
Boom 190 cm / 6' 3"
Mast 465 cm / 15' 3"