If you're thinking about a replacement part for this added anti siphon nozzle, it's an add on device and doesn't come with it.
In fact it may be very difficult to remove it.
View attachment 20624[/QUOT sometimes the (threads) are actually a spring if you pull away while you unthread it may come off...another option is to cut it off with a Dremel tool but not deep enough to cut the threads on the actual silcock you cut it in 2 spots close togetherpry that cut piece out the spread apart with s screwdriver...
or cut again...