Which I specified mostly for the ease of furling the mainsail. But it comes with it's own characteristics like setting the batten tension.

Installing them for the firs time, they go through the full length pocket into a car slot sewn on the luff. Once the luff end is inserted, the leech end of the batten, is held in with a Velcro strap. The "batten stuffer" slips into a pocket on the end of the Velcro strap, and you "stuff" the strap into the pocket which tensions the batten. The farther you push the Velcro stap over the batten, the more camber you put into the shape of the main.

Hope that makes some sense, Craig.