Who knew how difficult it was to find humidifier filters? We use our humidifier a lot so it was about time to change the filter. During one of our shopping trips, we tried to find the right match to our machine. Unfortunately, it didn't seem like the store had the correct filter. We bought one that we thought was right, but it wasn't. I think my husband managed to exchange it for the right filter. I know he put a new one in. I hope it was right!