I use them on my 3 roos in an urban setting. They do not completely stop the crowing, but they do significantly dampen the volume. Mileage varies per individual roo and sometimes they're just so stubborn that a no crow collar won't work at all. Properly applied and cared for, they're fine for your boys. One caveat though, use crumble feed. pellets have the potential to get lodged in their throat with a collar on and can put your roo at risk. I got mine from
https://nocrowroostercollars.com/, and they work as advertised. I know they're a touchy subject here on BYC, but myself and a lot of folks in my area use them quite successfully. I have no idea what shipping costs to OZ might be from that site, but you can probably find some DIY examples on the internet and make some for yourself.
Maybe talk with your neighbors first. See if they mind you getting a roo. Bribe them with fresh eggs and ear plugs, it goes a long way.
