“I used these to cap off all of my rainbird 1800 spray heads in order to see if there were any leaks in the the system. I did find that I had one bad head and replaced it. Once it was replaced, when I turned this zone on and then off, all of the caped-off heads remained in the popped-up position, indicating that there were no longer any leaks in the zone.
I'm not sure why rainbird doesn't make anything similar.”