There are several videos on Youtube that shows a rooster collar.
is one of them.
After viewing several, it appears that the results will vary from bird to bird, how you use it, how tight etc etc. Most people say you should just make your own, which when you look at the price they want for...
Ive heard of yard birds, so I guess in city folk's closed little minds, yard birds lay yard eggs. It makes sense!! You want to really have fun with them, remind them where ALL eggs come out of :D, and that white thing at the end of their egg, that the rooster left???? yah, I love people...