I've seen them on Ebay, they are shaped kinda like a hershey kiss with a bite out of it. They are advertised as a kissy pouch.
I have been to that site, it's great. even with my limited knowledge of sewing I was able to make several of the cage pouches and they don't look half bad if I say so myself.
It is starting to get warm here some days anyway, ya never know about kansas city weather here lately, and don't want to just wear a bonding pouch with a zipper as I am afraid the kids will get to hot. I tried my hand at putting in a screen but that was not a pretty sight.