Test it on your faucets at home. Should have enough of a variety of faucet types at your house that at least one should work. If they don’t, might be doing it wrong. I could be wrong though. I’ve had to hunt to find the right one, and sometimes I think the right one didn’t work the first time for whatever reason b/c it seems like I go through the whole selection more than once. We carry a pipe wrench in the van to get the screen attachments off without (hopefully) any damage.