JR,
A regulater is a sail that gets heavier toward the leech. As it gets
rolled up, in a reefing situation, it's exposed area is heavier and
flater

The Kappa cut uses parallel panels sowen together to shape the sail.

The 10-40 is the wind range it was designed for.

It isn't the greatest light air sail but it still works. I carry a 170%
Drifter for very light air, which I set free standing behind the rolled
up furler. The Drifter is a big, light weight sail, that is easy for a
old man to handle in easy conditions

Heading down wind I often fly both; Drifter and the pulled out Furler,
both poled out. It has made the Spinnaker's time of use rather slack at
best.

Ole Thom