Larry,
Ours came with the boat, from a previous owner. I believe it is by Hathaway Reiser and Raymond, but not positive on that. It is well made, in excellent condition, but is probably 15+ years old (has not been flown a tremendous amount).
Ours seems to be "full sized". I often wish it were a bit smaller. Back in the early days of asyms, there was a tendency to "max out" the dimensions of these sails. In my experience, they can get a bit cumbersome when they are huge like that. Ours is manageable, but if it were 90% of the size all the better. A fairly high clew is also helpful, as one big complaint with these sails is obscured forward visibility.
Ideally you'd have two of these, a larger one made from .6 oz or .75 oz material, and a smaller one from 1.5 oz material for heavier air and/or tighter reaching. Most of us don't have the space or budget for both. So usually we compromise with a .6 or .75 oz chute designed and sized more for light air.