Faster's right, you can rig a line to these, they make the sail a little easier to take in since you're collapsing it from the middle.
But if you don't want to rig two extra lines to tangle with your pole (it's a symmetrical spin. with a pole?) just take it down the old fashioned way--let the pole forward, ease out the guy while you grab the clew on the sheet end and gather the whole foot in your arms so the chute is collapsed in the blanket of the main. Then someone lets the halyard off gradually as you stuff it into the bag, turtle, cockpit, cabin, or whatever.
If it's an assymmetrical "Gennaker", tacked down to the bow, essentially same deal. Main thing is to get it blanketed by the main, so it's not drawing while you're trying to douse it. Then your job is easy, it's just cloth, with no force on it.
Apologies if you already know all this. But it is the "Learning to sail" topic.