Honestly, I think that you should have someone have the phone camera at the ready, you have a neighbor run at you growling and snorting and stuff and you spray them starting at 25' , then at 20', 15', etc....then post the video on here. Its not an exact science, but it would be worth a laugh. I would also venture to say after the try at 25' you will need to find a new neighbor to try it at 20. It works.....just don't buy the cheepo little pocket can. Frontiersman....about 50.00