There's enough there for about 8 small jars of preserves. I know, because I already cooked the other half and they are cooling on my counter, now:
We've never really figured out what these fruits are. They're about the size of cherries, but they definitely look like plums, inside and out. It's not a cherry pit, either - nope, it's a plum. But little ones. So we just call them cherry-plums and let it go at that.
This was my first experience using pectin. I have an extra jar that I didn't have space to boil, so when it cools, I'll have a chance to check out my attempt. I do have to say though, that the jam tastes good!